The Problem with Anchoring

A major idea due to Jarrett Walker, adopted with gusto by Vancouver’s Translink, is that transit should be anchored at both ends. That is, transit lines should have busy destinations at both ends, and should strive to reorient development such that the maximum intensity is near the ends. I was skeptical about this from the start, but now that I live in Vancouver and see the practice every time I go to UBC, I realize it’s much worse.

The Translink document justifying the layout has a figure, Figure 10 on PDF-page 15, showing that if development intensity peaks in the middle, then the bus will be overcrowded in the middle and empty at the ends. In contrast, if development intensity peaks at the ends, then the bus will be crowded but not overcrowded the entire way. Or, as Jarrett says, “If a transit line is operating through an area of uniform density, about 50% of its capacity goes to waste.”

Both in theory and in practice, this argument fails to note that a bus with development at the ends will be overcrowded the entire way, because people will travel longer. If UBC were located around Central Broadway instead of at the very west end of the metro area, people would just have shorter travel time; at no point would there be more westbound a.m. crowding because at no point would there be more westbound passengers traveling at the peak. There would be more eastbound a.m. crowding, but that’s not the Broadway buses’ limiting factor. Of the top four routes for passups, which have far more than the fifth route, three are east-west with strong anchors at both end (UBC at the west, the Expo Line at the east) and one, the third worst, is a C-shaped amalgamation of two north-south routes, with peak development downtown, in the middle of the C.

On a theoretical level, development intensity is a result of high land prices justifying high density, and in an urban area high land prices come from proximity to other urban land. In cities without topographic or political constraints on development, the CBD is always near the center of the metro area, and in coastal cities the CBD is usually near the shore but near the center along the axis parallel to the shore. Major secondary nodes usually arise in areas close to many suburbs, often the richer ones, and there’s travel demand to them from all directions: see for examples La Defense near Paris and Shinjuku and the other secondary CBDs in Tokyo. Some of those nodes happen to be near the shore (UBC, Santa Monica and Long Beach, Coney Island) but most aren’t. Any newly-built anchor will sprout further development around it unless there’s very strong local resistance. To connect all those neighborhoods that lie beyond the secondary CBD, unanchored transit lines are then unavoidable.

We’re left then with anchors that are at geographic edges, such as on shores. Those raise travel distances, because people can only live at one direction from them, so for a given residential density they will have to travel longer on average. They look attractive to transit managers because they also make the buses more uniformly full, but they’re worse for passengers who have to travel longer, often standing the entire way because of overcrowding. They’re not even good for transit agency finance, because urban transit invariably has either flat fare (as is the case within Vancouver proper) or fare that depends on distance fairly weakly. Short trips generate as much or almost as much money for the agency while requiring less effort to run because of lower crowding levels. Trips in which most passengers ride end to end are the least efficient, unless they can overcome this with very high crowding levels all day.

Now, what does help finances as well as the passenger experience is bidirectional demand. Anchors are good at that. However, what’s just as useful in cases of asymmetric peak demand is destinations that are short of the most crowded points. For example, in Manhattan the north-south subways fill as they go southward in the a.m. peak. This means that commercial buildings north of Midtown, generating passenger traffic that either is northbound (hence, reverse-peak) or gets off the train before it gets the most crowded within Midtown, add ridership without requiring running more trains. The MTA’s guidelines explicitly call for matching frequency to demand at the most crowded point of each line based on uniform sets of peak and off-peak crowding guidelines. This favors not outlying anchors, but development sprinkled uniformly along transit lines outside the CBD. The same development in the North Bronx would have low transit mode share (UBC has high transit mode share, but it’s at a geographic edge, and on top of that it has a huge body of students), while on the Upper East Side and Upper West Side it would have high transit mode share. The only outer ends where heavy upzoning is appropriate are those that aren’t really ends, such as Flushing and Jamaica, preexisting secondary centers in their own right to which people take the subway from the west and drive from the east.

De facto, Translink makes cost figures available for each bus route, and we can compare costs per boarded passenger on the east-west routes and on the north-south ones. The east-west routes have an initial advantage because they have bidirectional peak demand, whereas the north-south and C-shaped ones do not, and have few destinations short of the CBD, mainly just on Central Broadway or Commercial Drive. Despite this inherent east-west advantage, cost per rider is not lower on the east-west lines. Of the top ten route numbers, there are five balanced east-west routes: 99, 9, 41, 49, 25; and four north-south or C-shaped ones serving downtown: 20, 16, 8, 3. (The 135 is east-west connecting downtown with SFU, and could be included in either category.) Going in the same order as above, the east-west routes cost $0.61, $1.21, $1.10, $1.31, $1.47 per passenger, while the north-south ones cost $1.02, $1.29, $1.09, $1.06. (The 135 costs $1.32.) The three routes that interline to UBC on 4th Avenue – the 4, 84, and 44 – cost $1.62, $1.30, and $0.78 respectively, averaging to $1.30; the 84 is anchored at the Millennium Line, the 44 is anchored downtown, and the 4 is anchored downtown but also continues farther east.

The 99 is much cheaper to run than the other routes despite its high proportion of end-to-end ridership, but it is also critically crowded and benefits from multiple peaks as it serves both a secondary CBD and a university; it is also express, which among the other routes under discussion is only true of the 44, the 84, and the 135. Among the local routes, the north-south routes are actually a bit cheaper to run than the east-west routes even if we exclude the 4 as a not fully anchored exception. The 20, the 8, and the 3 all have their maximum development intensity at the downtown end with some extra development in their inner areas, near SkyTrain and Broadway, and a lot of medium-intensity development at the tail. This provides suitable short-of-CBD destinations adding passengers at low cost.

For one measure of productivity, we can divide the number of boardings per hour by the average load. The result is the reciprocal of the average number of hours spent by each passenger on the bus; a higher number means each passenger spends less time on the bus, indicating higher turnover, or equivalently more revenue relative to crowding. The 99, 9, 41, 49, and 25 have ratios of 2.79, 3.13, 2.65, 1.93, 2.13; the 20, 16, 8, and 3 have ratios of 3.26, 2.73, 3.57, 3.24. The 20, 8, and 3 again look very good here, helping explain their low operating costs and also their low crowding (they rank 12th, 27th, and 20th respectively in passups but 2nd, 6th, and 7th in weekday ridership). The 49 and 25, both highly anchored routes, do not look as good, and indeed have many passups relative to ridership (they rank 1st and 4th in passups but 8th and 10th in weekday ridership); they have the redeeming feature that they protrude slightly into Burnaby, where zonal fares are higher, but judging by a map of the passups, the 25 seems to get a large majority of its ridership strictly within Vancouver, with Nanaimo Station as the eastern anchor rather than Brentwood.

We can extend this analysis further by looking at New York’s bus operating costs. Cap’n Transit laboriously compiled a spreadsheet of operating cost per New York City Transit bus route. Within Manhattan, the pattern is that east-west routes have much lower operating costs per passenger than north-south routes. The M15, the busiest route in Manhattan with ridership comparable to that of the 99 in Vancouver and with the best finances among the north-south routes, almost breaks even on direct operating costs; most of the major east-east routes are outright profitable counting only direct operating costs. The key difference is that the east-west routes are much shorter, so passengers are paying the same amount of money for less distance. In his own analysis, the Cap’n notes that the express bus with the best finances is also one of the shortest, and that in general the profitable-after-direct-operating-costs buses have many transfer points to the subway, which suggests short trips as well.

Having seen more evidence for the theory that good bus finances require short trips rather than endpoint anchors, we can go back to Vancouver and compare more routes. The busiest north-south route not on the above list, the 2/22, works more like the 16 than like the 20, 8, and 3: not only is the 22 C-shaped rather than terminating downtown, but also it serves corridors that are less busy than Commercial and inner Main, reducing the availability of short trips. The shorter 2, overlying the longer 22, has 3.42 boardings per hour per load, but still costs $1.43 per rider; the 22 has only 2.15 boardings per hour per load and costs $1.61 per rider, and also ranks 3rd citywide in passups versus 11th in weekday ridership. On both the 16 and the 22, the north-south legs (Arbutus and Renfrew for the 16, Macdonald and Clark/Knight for the 22) are streets that aren’t very busy by themselves, but instead act as important cross-streets for Broadway and other east-west streets. Here are Knight, Renfrew, Arbutus, and Macdonald, and here are, by contrast, Commercial, Fraser, and Main, all around the same cross avenue (near but not at 16th).

The same is true of the east-west buses. The 99, 9, and 41 have better finances than the 49 and the 25. They also do better on passups, ranking 2nd, 11th, and 10th versus 1st, 3rd, and 4th in ridership. The 99 has much better finances than all other buses, which can be chalked to its overcrowding, but ultimately comes from continuous intense development all over Broadway making it a prime corridor. 41st has some of this development as well: here is how a strip of it looks close to the cross street I live on. Compare this with 49th and King Edward around the same cross street. This is not cherry-picked: 49th and King Edward just aren’t commercial streets, and even where they act as important cross streets such as at Cambie there’s not much development there. Of course 4th does have this commercial development and is almost as expensive as 49th and King Edward, but its commercial development is discontinuous, and the relatively intense section between Granville and Balsam is short enough that people can walk it.

So what this means for transit-friendly development is that it should not worry about anchoring, but instead try to encourage short trips on local transit. In his original post about Vancouver’s anchoring, Jarrett says of Marine Drive, at the southern edge of Vancouver proper, “From a transit efficiency standpoint, it would be a good place for some towers.” This is not good transit: from the perspective of both costs and ridership any residential development south of Broadway in which people take the bus downtown is equivalent, so might as well put it immediately south of Broadway or at King Edward, 41st, or 49th to connect with the east-west bus routes and let people live closer to work. Commercial development, too, is best placed short of downtown, because if it’s on Marine Drive people will drive to it whereas if it’s along the blocks immediately south of Broadway many won’t.

Better would be to do what Vancouver hasn’t done, and encourage medium-intensity development all over the major corridors, of the kind that exists on Commercial, Fraser, Main, and 41st and allows their respective bus routes to serve productive short trips, generating low costs without excessive crowding. Towers on Marine Drive, to the extent that their inhabitants would even use transit instead of driving, would clog all the north-south buses. Mixed-use medium-rise development running continuously along Arbutus (which already has an abandoned rail corridor that could make a relief light rail line if the Canada Line gets too crowded) and the major east-west corridors would have the opposite effect, encouraging local trips that wouldn’t even show up at the most crowded point of the line. I’ve argued before that this urban layout is good for walkability, but it appears to also be good for surface transit productivity.

This is also relevant to upzoning around SkyTrain stations. There has not been so far any upzoning around Cambie, even though the Canada Line has been in operation for 3.5 years and was approved for construction over 8 years ago, but there will be some very soon. Vancouver’s draft plan, as shown on PDF-pages 26-27, permits 4 floors of residential development on the cross streets with the stations, 6 on Cambie itself, and between 6 and 12 with mixed use near the stations themselves. Continuous commercial development will be permitted only on Cambie between 41st and 49th. This will be of some use to the east-west buses because there will be more destinations at Cambie, but it will not create the same variety of small destinations available on Main, Fraser, 41st, Commercial, and Broadway, not without further upzoning near intersections that are nowhere near SkyTrain. It’s better than the towers of the Burnaby stations, but it’s still not very good. There is commercial upzoning near Marine Drive, but that can’t be very transit-oriented given the location, and it can’t do much for north-south bus productivity since in the nearby neighborhoods car ownership is high.

It’s too late to change the rezoning plan to permit more linear commercial development on the cross streets, but it’s possible to do better when Vancouver gets around to building Broadway SkyTrain. On Broadway itself, general intensification, allowing more residential density and replacing residential-only zoning with mixed-use zoning, should suffice. There is continuous commercial development from east of Cambie to west of Arbutus, with a two-block gap to Macdonald, and a one-block gap between Macdonald and Alma; both gaps are within a few hundred meters of the cross streets and can be closed easily. The Alma-Sasamat gap on 10th is probably too hard, though. The Arbutus-Macdonald gap on 4th can also be closed, though those blocks are nearly a kilometer from where the stations would be. But it’s as important to allow commercial zoning extending as far south as possible on the major north-south streets, especially Arbutus. Continuous mixed-use zoning should extend at least as far as 16th, and maximum residential density should be at a minimum 4 floors and ideally 6, as Arbutus, Macdonald, and 16th are very wide and the intersections feel out of scale to the current 1-story development.

Of course, this principle of design is true only of urban transit, both surface and rapid. Once the stop spacing increases to regional rail levels, it is no longer feasible to have continuous commercial development, and usually the street networks of the different suburbs are separate anyway without continuous arterials. In all cases it’s important to allow commercial zoning around stations, but the spiky development characteristic of the Expo and Millennium Lines becomes a better idea the longer the stop spacing is. Endpoint anchoring also becomes more justifiable at near-intercity scales, such as New York-New Haven or Boston-Providence: the fares are closer to proportional to distance, and also neither New Haven nor Providence is sprouting suburbs at such scale and distance that it’s justifiable to extend Metro-North or the MBTA with their usual stop spacing past those cities. But at the scale of urban transit, or even inner regional rail, the natural endpoint of a line is not a secondary anchor, and transit agencies should control peak-to-base ratios by commercial upzoning along corridors and near many stations outside the CBD rather than by making people ride transit kilometers longer than would be necessary if the zoning were different.


  1. Alan Robinson

    Alon, I’m going to dissent to most of this article, then restate the problem.

    You’ve examined that the double anchored east-west bus routes in Vancouver are in general have passengers traveling further, are more expensive to run, and have more pass-ups than the single anchored north-south routes. You attribute these facts to the anchoring of the routes. You then conclude that developing endpoint anchors for transit routes increases the cost of providing transit service. As an aside, you also look at the cost of providing bus service along short vs. long routes in NYC.

    First, in Vancouver, the east-west anchors create a much deeper trough in demand than downtown and development along the north-south routes. I suspect that it is the additional cost of providing extra peak tripper and low demand mid-day, night, and weekend service to the 25 and 49 that make them more expensive than the 16 and the 8. This effect might be separated from the anchoring effect by looking at the cost of providing peak-only trips.

    Increasing development along the east west corridors would decrease the cost per trip along that corridor by encouraging shorter trips along those routes and by spreading the peak. This is not an argument that directly leads to lower network operating costs. Without increasing residential density, these off-peak trips are now spread between both the north-south and east-west routes. This will likely marginally decrease the overall distance traveled, but it also demands higher off-peak frequency on both sets of routes for the same number of trips, increasing costs overall.

    It is misleading to comparing the cost effect of anchoring to the cost effect of route length. Short routes, almost by definition, are anchored at both ends and force short trips. It’s also difficult to measure overall cost per passenger on short routes as the number of transferring passengers will be much larger.

    You’ve also remade the point, that I had previously dissented to, that continuous development along Vancouver’s commercial corridors would improve the urban environment. Clustering of development at important crossing points or at the center of a community is efficient when there is insufficient local demand to develop a continuous commercial corridor. This allows the most number of people to do their errands without having to get on a bus at all, while making combined trips easier for those who need to travel anyways.

    Now to where I agree. Development encouraging long travel distances should be avoided. Placing a commuter campus on a peninsula or a mountain dramatically increases travel distances. This would not be a problem for UBC if Point Gray was sufficiently dense to house all the students, services, and staff that are required, but it instead acts as a barrier to those who need to travel from more affordable locations. As UBC and SFU are developed into a mixed-use community and less of a commuter campus, hopefully the demand put on transit can be reduced in the long term (I have my doubts). I do not agree with you that Marine Drive development should be placed in this category.

    When Jarrett writes about the benefits of anchoring transit routes, he points out that the benefit is in utilizing capacity that would otherwise be wasted at the end of a route. As mezzanine pointed out in the comments of his analysis of Vancouver’s grid, “the major problem with the UBC anchor is that it works too well”. It no longer just fills unused capacity, but rather drives the demand as a unipolar anchor during peak times. That’s the problem with anchoring.

    • Alon Levy

      The problem with the unused capacity argument is that it’s not the job of a transit agency to fill buses. As I told Jarrett below, there are two separate metrics there: full buses measure passenger-km, whereas transit agency finances as well as passenger benefits are proportional to passenger boardings. Those two metrics are highly correlated and this makes it look like raising crowding is an automatic raise in productivity, but in fact anchoring raises the crowding-to-productivity ratio and also requires people to have longer commutes.

      You’re also making the argument I’m criticizing look a lot milder than it actually is. Translink really thinks that if the route is anchored then there will be consistent crowding levels on the bus whereas if peak development intensity is in the middle then the bus will be overcrowded in the middle; this is what figure 10 of its document shows. Jarrett really did say that Vancouver should encourage higher density along Marine Drive, farthest from the downtown core. It all works out perfectly if the goal is to maximize passenger-km, but from the perspective of either the taxpayers or the riders, there’s no gain from making people live out on Marine Drive instead of on King Edward or immediately south of Broadway.

      What you say re new development and off-peak ridership isn’t really an argument for anchors. Buildings on Marine Drive generate traffic; so do buildings on 16th. In general, the marginal cost of new off-peak riders is low, and the marginal cost of riders at any time of day whose trips do not include the most crowded point is zero. The 25 is crowded the entire way, but there’s more space on the 16 and the 22 as long as the riders don’t go downtown, there’s space on the 49 west of Cambie, and there’s space on the 20, 41, 8, and 3 in general. Definitionally any new rider would have to get some extra off-peak frequency, but that’s true metro area-wide. So the question is whether you want your new riders to be peak or off-peak (off-peak is better), and whether you want their trips to be long or short (short is better).

      I still think that the local demand is in fact sufficient to develop somewhat continuous commercial corridors. 4th and Broadway both have 2-block gaps. They also have higher residential density nearby than Hastings and Commercial, which nonetheless support more or less continuous commercial development along the inner half of the route of the 20. The SkyTrain station helps, but there’s continuous development many blocks away from it. In the area under discussion re anchoring, King Edward and 49th both have stations on the Canada Line that can provide the demand (to say nothing of students at Langara College who have nothing to walk to). Out on Arbutus/West Boulevard there’s already some development; West actually has continuous development from 41st to 49th, but it stops at 49th and there’s nothing on 49th itself in that area. In the context of the upzoning Vancouver is already seeking there should be more commercial development on those cross streets to accompany increased residential density. Vancouver really is doing commercial upzoning in Marine Landing, which doesn’t even have a major bus, while neglecting same on King Edward and 49th. Look at the draft plan’s PDF-pages 58-69 to see what scale they’re proposing to build there, and then look at the preceding pages, 32-57, to compare what they’re proposing to build in areas that already have a skeleton of walkable demand. It’s the TOD equivalent of Bloomberg’s refusal to spend money on a subway station at 10th Avenue because that area is already developed.

      • Alan Robinson

        Hi Alon,

        I’m apologize for being unclear regarding commercial development on N-S vs. E-W streets. I was trying to explore what effect the non-isotropy of development in Vancouver would have on the route operating costs you claim are primarily affected by anchoring.

        “there’s no gain from making people live out on Marine Drive instead of on King Edward or immediately south of Broadway”.
        Only if most residents at Marine Drive will have to travel downtown during peak periods. One of the main concepts of the development is to have all of residential, commercial, entertainment, industrial, and offices in close proximity in order to minimize travel requirements. For those needing to travel, Marine Drive is a transit and cycling node, allowing for easy connections in any direction and to multiple
        job centers in Vancouver, Richmond, and south Burnaby. (and yes, the 100 is a major (FTN) bus route). In contrast, those moving to King Ed may have to travel a shorter distance to downtown, but they still have to travel some non-walkable distance to work. There’s also the argument that encouraging development anywhere in Vancouver is still better than development in most other parts of the region.

        I’m not sure the type of commercial development along Hastings and along Broadway or 4th can be easily compared. The development on Hastings east of Glen Dr. (and along Kingsway for that matter) is much more automobile focused. Also, while the gaps in development along Broadway and 4th could, but not necessarily should, be filled in the short-term, I don’t see how the full length of King Ed or 49th and its cross-streets could be developed over even a 50 year time scale without oversaturating the market with commercial space.

        I have one new point in support of anchoring. Anchoring also allows a larger proportion of trips to be a one-seat ride, providing greater access to those at the anchor point in all directions. This doesn’t work if you’ve restricted the available directions of travel and destinations by locating on a peninsula.

  2. Jarrett Walker

    Anchoring is a principle for achieving more ridership, and thus more public value, given a fixed budget for operations. This is a mathematical fact.

    Overcrowding, when it occurs, requires supplementary service or larger vehicles (or rapid transit). TransLink, unfortunately, doesn’t have a suitable contingency budget for putting out those supplementals in response to demand, especially given the high costs of short labor shifts.

    For network design, however, crowding is mostly evidence of success. Overcrowding doesn’t mean there’s a problem with the network design. It means that transit is succeeding and that supplementary frequency is needed to handle peak demands.

    • Alon Levy

      I don’t think it’s actually a mathematical fact. You’re confusing two sets of related, but not identical, service metrics. Crowding measures passenger-km per bus-km. But Translink doesn’t get paid in passenger-km; within Vancouver and the Endowment Lands, it gets paid per passenger. The alternative metric is boardings per service hour. It is not useful to Translink finances to have longer trips. It is not useful to passengers, who have to endure longer commute times. Longer trips can be beneficial if they allow people to spread out and reduce land prices, but this effect isn’t really in play when you’re deciding whether to upzone around Marine Drive or just south of Broadway.

      I also don’t think that there’s a single person who’s taking the bus to UBC who wouldn’t still take transit if UBC were located on Central Broadway. So developing without an anchor would not actually depress ridership. It would mean some buses are going to run emptier west of campus, but it’s not going to reduce agency revenues at all, but instead people would be paying the same amount for a shorter trip. Finances would actually improve because a lot of buses could turn at Arbutus, and of course the subway would only need to be built to Arbutus rather than all the way to the edge of the peninsula.

      • Alexis

        I also don’t think that there’s a single person who’s taking the bus to UBC who wouldn’t still take transit if UBC were located on Central Broadway.

        That seems pretty unlikely to me. The UBC campus is relatively inaccessible to walking and biking: far away and up a steep hill, with a largely undeveloped belt between it and the nearest neighborhoods. If it were on Central Broadway, some or all that wouldn’t be the case, and people living in the surrounding areas who currently take transit because of the limited accessibility would be able to easily walk and bike there.

        • Alon Levy

          I’m not actually sure there would be too much walking – Central Broadway is not a residential area, and putting UBC there would make it even less residential. Maybe people would be walking from south of 12th, but a lot of people who live in that area aren’t even taking transit to UBC but driving there. Anecdotally, I know few UBC students who live in Kits and Point Grey; most live farther away and would still be taking transit, while faculty members live in Point Grey, Kits, and Fairview, and have a fairly low transit mode share. In fact because people from the southern parts of the West Side would have the Canada Line whereas today they can drive on King Edward or 49th or Marine Drive, putting UBC on Central Broadway should increase the transit mode share.

          Besides, I think it’s perverse for a transit agency to have an official policy of supporting development that’s hard to walk or bike to. The competition for transit is cars. Walking and biking are complements. I really hope that Translink said that anchors are good because of the subtle mistake of confusing crowding with productivity metrics, and not because it’s surreptitiously trying to make Vancouver less walkable so that it can get more captive riders.

      • Jarrett Walker

        Alon. I’m talking about the efficient use of service resources for the purpose of optimizing access, and its related sustainability outcomes. It’s not about fare revenue!!! You sound like Margaret Thatcher.

        • Alon Levy

          You’re not talking about optimizing access, not when you openly call for zoning specifically so that people have to live far from where they work. It’s not all about filling vehicles. My point about revenue is that there is nobody in the transit ecosystem who has any interest in maximizing passenger-km – certainly not passengers, who’d rather live on King Edward than on Marine Drive, but also not the transit managers. Raising passenger-km via edge-of-city upzoning just to fill buses is not sustainability; it’s greenwashing.

          • Nathanael

            Jarrett is thinking narrowly, and honestly thoughtlessly. You’re right about this. There’s a huge difference between connecting between existing anchors — sensible — and suggesting the construction of “New Towns” out in the middle of nowhere as “anchors”, which it appears Jarrett is *actually suggesting*.

            Get a clud, Jarrett.

          • Nathanael

            Or even a clue. 🙂 I’m not sure what good a clud would do. I’m not even sure what a clud is.

          • al

            There are some good examples of what Jerrett is proposing. In the Bronx, there is a cluster of schools and hospitals in Bedford Park, Norwood and Jerome Park area. 4, D, and B trains heading north during peak hrs end up in these neighborhoods. Considering how crowded trains get during peak hrs in NYC, it would be a good idea to locate HS (and set up student enrollment catchment areas) at locations to take advantage of reverse peak capacity. Brooklyn College, Midwood HS and SUNY Downstate Hospital are another example along the 2 and 5 trains.

    • anonymouse

      Just thinking in terms of revenue, anchoring is a way to achieve turnover, that is, getting more than one rider to occupy a seat on a given trip, which tends to increase passenger boardings per bus-km, which makes the line more profitable. But there are other ways of achieving the same thing: if there is decent density along the whole corridor and frequent grid connections, there may end up being a large number of short trips. Having a reverse-commute market helps as well, for routes going through downtown, or just to avoid empty deadhead trips. Too-strong anchoring can actually work against this goal of turnover if the anchors are strong enough that there is significant ridership all the way from one end of the line to the other, as seems to be the case with UBC routes in Vancouver.

    • Nathanael

      I think there’s a subtle distinction between anchoring in *route design* and anchoring in *development*.

      If the anchors *already exist* and *have already been built*, it makes sense to run the route between them. This is Jarrett’s point.

      It does NOT, however, make any sense to BUILD new anchors out on the far ends of lines. This is Alon’s point.

  3. JJJJ

    Interesting. It reminds me of when I lived in DC, in Takoma. That was the last stop where you could find a seat. That is, the closer you live to your destination, the less comfortable your ride will be. Does that make sense? Punishing people for living closer by making them stand like sardines, while the suburban riders get ample room to read the paper?

    • Anon256

      The suburban riders still have to stand for a large part of their return journey home.

      For me (and I think most people) disutility of standing increases more than linearly with time standing, so giving people with longer trips some priority for seating seems fair.

  4. KHH

    Better would be to do what Vancouver hasn’t done, and encourage medium-intensity development all over the major corridors … Mixed-use medium-rise development … good for walkability … good for surface transit productivity.

    Yes, yes, yes. Tons of midrise development is good. Zoning the vast majority of your city for 5,000 square foot single family lot sizes, and then allowing towers in a few headline districts, is bad. Organic townhome, condo, and apartment construction in formerly single-family neighborhoods is good. Allowing a few NIMBYs at a neighborhood meeting to overrule the best judgement of planners and developers is bad. Preserving your zoning code in amber so that the single-family districts next to a brand new light rail line still state that horse barns are only permitted if they were built before 1954 is baaad.

    Inner-ring Houston, Seattle, LA. Walk to the store. Bike to the other store. Bus to the job, cab to the show, drive to the beach or your friend’s pad. Cities that are friendly to all modes. That’s the life.

  5. mike0123

    Anchoring is useful to justify predictable and consistent operation of routes over the full length of streets and to justify extensions to routes to reach useful connection points at anchors. Buses on streets without a secondary anchor might more likely be short-turned to increase capacity on the busier part of the route. Reduced frequency on the less busy part of the route reduces makes the route less useful as part of the network.

    The combination of the short-turning route and the full-length route can also lead to issues with bunching or inconsistent headways as more people use the full-length route near the ends of the short-turning route.

    The bus network in Vancouver would be better connected to Richmond if more routes in South Vancouver were extended to Marine Drive Station or the Knight Street Bridge. The extensions to the 3, 8, and 20 that would be required to make these connections are not long, but these two locations are not large enough anchors to justify the extensions except for every other 3.

    On the other hand, the 3, 8, and 20 are less busy on the downtown-anchored parts of the routes than on the parts near Skytrain. The parts of these routes on Hastings add little usefulness to the transit network despite their endpoint being the region’s largest anchor. The reason is most likely that connecting via Skytrain instead of Hastings is faster from nearly all points south of Hastings to nearly everywhere in the region, including downtown.

    The 3, 8, and 20 might be improved by cutting off the anchor at their northern ends and adding an anchor at their southern ends.

    • Voony

      Fully agree with this comment.

      Anchoring is simply good policy… the “problems” mentioned in the article, are not fundamental problems, but as mentioned before, symptoms of the success of the approach.

      • Alon Levy

        It matters that the anchored routes are more crowded relative to ridership than the unanchored ones. Translink sells the anchoring approach specifically as a way of avoiding overcrowding – see Figure 10 again. None of what I’ve said about anchoring is a strawman; it comes from things Translink and Jarrett have actually said that Vancouver is actually implementing, i.e. the Marine Landing rezoning.

        • mike0123

          The development of East Fraserlands – the largest proposed development in Vancouver – will hopefully justify a more legible network in the southeastern corner of the city. Establishing a large anchor further south should force the separation of the 26 into two routes that continue the pattern of Vancouver’s gridded network. The existing route network there is a tangled mess because:
          1) the 49 makes a detour to serve an old strip mall, and
          2) the 26 makes a loop between adjacent SkyTrain stations without going further north to cross e.g. the Millennium Line.
          Both of these issues make the network less useful than it should be.

          A more legible network would be realized with:
          1) a route on Rupert north of 29th Avenue Station and on Kerr further south extending to the new anchor,
          2) a route on Boundary north of Joyce Station (connecting to Gilmore Station) and on Tyne further south possibly extending to the new anchor, and
          3) removing the detour from 49th Avenue on the 49.

        • Nathanael

          Yeah, Jarrett has gotten dangerously confused.

          Anchors are good policy as a *route design* tool. They are NOT good policy as a *zoning* tool. As a zoning tool, they’re *nuts*, which I think is your point.

          • Adirondacker12800

            So Tyson’s Corners shouldn’t redevelop itself into a second Rosslyn-Ballston corridor?

          • Nathanael

            Given that Tyson’s Corner is already developed to the point of having car congestion, *and that Dulles Airport is already present as an anchor on the far end of the line*, this is not the situation I’m talking about.

            However, there are proposals to extend the Dulles Metrorail line beyond the airport and then to upzone waaaay out there. *That’s* what I think is a bad idea.

          • Adirondacker12800

            I don’t think the people in Virginia are …. stupid,…. enough to repeat the BART to San Jose experience.

        • mike0123

          Vancouver has an arterial network with a spatial frequency that enables a walkably efficient (i.e. coverage without duplication) bus network design. Establishing new anchors will not change the basic structure of the network, except at its edges. Establishing a new anchor immediately beyond the edge of the existing network can justify extending the structure.

          UBC is an anchor that extended Vancouver’s network structure and justified better east-west coverage and frequency. UBC generates high peaks in ridership each hour, matching its schedule, which causes crowding. Institutions with less rigid schedules or anchors with more than one institution should have less crowding.

          Strongly anchored networks have routes that duplicate coverage near anchors. Burnaby has five anchors where practically all high-density mixed-use development is focused. All bus routes begin and end in one of the five anchors, except for a shuttle connecting the one SkyTrain-less anchor to SkyTrain. Few of the routes are direct. Few routes can be frequent.

          Networks, in general, should not be designed by connecting anchors together in a way that establishes coverage. Anchors should only justify extending an already reasonable network at its edges. Extending Vancouver’s arterial grid network through Burnaby would be an improvement over Burnaby’s anchor-connecting network. Burnaby lacks an obvious arterial grid, but it is actually possible to construct a reasonable network out of the patchwork.

  6. anonymouse

    Having thought about this a bit more, I think I’m starting to understand what anchoring really means: and anchor is a “destination” and that can be important for routes, and cities, where everything aside from a few clusters of “destinations” is just a uniform mass of residential “origins”. And in that case, a route with an anchor at one end would indeed end up being under-used at the opposite end, and having another anchor there would indeed allow the buses to fill up for more of their journey. Taking the logic in the other direction, a route that just goes through residential “origin-land” would have no anchor at all, and would struggle to get any ridership.
    But what if you instead change the underlying assumption of the structure of the city? In Vancouver’s case this would be done with re-zoning with the aim of getting more commercial development and more “destinations” spread throughout the city along existing transit corridors and on existing nodes in the frequent transit grid. This makes for a much more even distribution of trips, and reduces the need for “anchors” to drive ridership, because now there are destinations all along the line. I would even call the transit line self-anchoring at that point, once the corridor has developed enough.

    • Nathanael

      “In Vancouver’s case this would be done with re-zoning with the aim of getting more commercial development and more “destinations” spread throughout the city along existing transit corridors and on existing nodes in the frequent transit grid. ”

      A healthy city from a “pre-Euclid zoning” period will generally have a long “commercial street”, and then residences immediately behind it on all the parallel streets. This means you can run your bus straight down the “commercial street”. Many people walk from their houses directly to shops or workplaces; most everyone else walks to the “commercial street” then catches the bus the rest of the way.

      The presence of a “mixed use” radius at each bus stop — commercial and residential within the walkshed of every stop — is much more effective than “anchors” at supplying all-day, along-the-line demand.

      This, therefore, is how the zoning should be done. Now, Jarrett thinks like a transit planner who has no zoning control, and therefore looks at cities and doesn’t see this as a possibility, except perhaps where it already exists.

      • Alan Robinson

        I agree the idea of commercial streets and the relation of mixed use to all-day transit demand. As I commented earlier, I disagree with Alon that this commercial street has to be continuous, or that all bus streets have to be commercial streets when there are intersecting commercial streets.
        However, I disagree with you that there is no positive effect in placing density at transit anchors. An anchor has better access to a large area of the city than some random point along a transit line. It is a desirable location for businesses and residents. For the transit agency, it increases demand at the ends of the route where excess service was going to be provided anyways in order to provide better connections. This is partially counteracted by the increased travel distances that some trips will require, but this is only a large problem when there is an anchor with a large imbalance of uses far from either residences or employment (this is the case for UBC, or Tsawwassen, not for Marine Drive).
        Downtowns are the biggest anchors of all. They demonstrate that there are immense benefits to having high density with better than normal access to other parts of the region. If we make Downtown the only anchor in the system, then we will have wasted capacity at the outer reaches of our transit system and overcrowding makes Downtown less accessible to those who live on the edge. If we have mid-level density everywhere, then we become LA.
        Anchoring is NOT *nuts*!

        • Nathanael

          The argument is over whether anchors should be artificially manufactured by zoning at the outer edges of a city.

          That is what I think is nuts.

          If there is an anchor other than downtown which is naturally developing, by all means use it.

  7. Joseph E

    The disagreement here is based on a goal of boardings versus distance; access vs mobility

    Anchoring destinations at the peripheral ends of transit lines are good for increasing efficiency on the basis of passenger km (miles) per vehicle mile, but it may also be true that centralizing destinations is more efficient from a standpoint of boardings per hour.

    Similarly, transit is most successful at increasing access to destinations in a city that is centralized as much as possible. But if you were the owner of a private, for-profit transit system, you might instead prefer to have some strong destinations at the edge of the city, or at least secondary centers halfway out from downtown, so that your transit vehicles would stay full for a longer portion of the trip. Since for-profit transport (whether buses, trains, taxis or planes) generally charges both for boarding and per distance, encouraging some long trips, especially in the off-peak direction or at off-peak times, would be more efficient and leads to higher returns for a given operating expensive, and especially compared to capital expenses.

    Seeing that the public is the owner of the transit system in almost every English-speaking city, the readers of the blog have an interest in maximizing passenger miles to get a better return on investment for transit capital and operating costs, seen in better farebox recovery ratios. Distance based fares will generally be necessary to make this happen. Is economic efficiency of transit more important that its effects on development of the city and livability? Perhaps not, but it is not unimportant. And as long as political goals require coverage service out to the far-flung urban sprawl of North American cities, building destinations for transit at the periphery of the city can help make those coverage routes more useful, while providing some walkable (or at least closer) destinations for the residents of that sprawl.

  8. Wanderer

    To me, anchoring focuses on using the anchors that exist. The initial segment of the Orange Line Bus Rapid Transit ended in the west at Warner Center, a major office park. By contrast, many commuter rail lines miss suburban employment centers that they could be serving, though short extensions might be required.

    • ant6n

      I think that may be the key to the difference of opinions. One is looking at anchors as a policy for development; the other is looking at anchors when designing or modifying the transit network given existing developments.

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