Train Weight and Safety

A recent New Jersey Transit train accident, in which one person was killed and more than a hundred was injured, has gotten people thinking about US rail safety again. New Jersey has the second lowest fuel tax in the US, and to avoid raising it, Governor Chris Christie cut the New Jersey Transit budget (see PDF-pp. 4-5 here); perhaps in reaction to the accident, Christie is announcing a long-in-the-making deal that would raise the state’s fuel tax. But while the political system has been discussing funding levels, transit advocates have been talking about regulations. The National Transportation Safety Board is investigating whether positive train control could have prevented the accident, which was caused by overspeed. And on Twitter, people are asking whether Federal Railroad Administration regulations helped protect the train from greater damage, or instead made the problem worse. It’s the last question that I want to address in this post.

FRA regulations mandate that US passenger trains be able to withstand considerable force without deformation, much more so than regulations outside North America. This has made American (and Canadian) passenger trains heavier than their counterparts in the rest of the world. This was a major topic of discussion on this blog in 2011-2: see posts here and here for an explanation of FRA regulations, and tables of comparative train weights here and here. As I discussed back then, FRA regulations do not prevent crumpling of passenger-occupied space better than European (UIC) regulations do in a collision between two trains, except at a narrow range of relative speeds, about 20-25 mph (30-40 km/h); see PDF-pp. 60-63 of a study by Caltrain, as part of its successful application for waivers from the most constraining FRA regulations. To the extent people think FRA regulations have any safety benefits, it is purely a stereotype that regulations are good, and that heavier vehicles are safer in crashes.

All of this is old discussions. I bring this up to talk about the issue of systemwide safety. Jacob Anbinder, accepting the wrong premise that FRA regulations have real safety benefits, suggested on Twitter that rail activists should perhaps accept lower levels of rail safety in order to encourage mode shift from much more dangerous cars toward transit. This is emphatically not what I mean: as I said on Twitter, the same policies and practices that lead to good train safety also lead to other good outcomes, such as punctuality. They may seem like a tradeoff locally within each country or region, but globally the correlation goes the other way.

In 2011, I compiled comparative rail safety statistics for the US (1 dead per 3.4 billion passenger-km), India (1 per 6.6 billion), China (1 per 55 billion), Japan (1 per 51 billion), South Korea (1 per 6.7 billion), and the EU (1 per 13 billion), based on Wikipedia’s lists of train accidents. The number for India is an underestimate, based on general reports of Mumbai rail passenger deaths, and I thought the same was true of China. Certainly after the Wenzhou accident, the rail activists in the developed world that I had been talking to stereotyped China as dangerous, opaque, uninterested in passengers’ welfare. Since then, China has had a multi-year track record without such accidents, at least not on its high-speed rail network. Through the end of 2015, China had 4.3 billion high-speed rail passengers, and by 2015 its ridership grew to be larger than the rest of the world combined. I do not have statistics for high-speed passenger-km, but overall, the average rail trip in China, where there’s almost no commuter rail, is about 500 km long. If this is also true of its high-speed rail network, then it’s had 2.15 trillion high-speed passenger-km, and 1 fatality per 54 billion. This is worse than the Shinkansen and TGV average of zero fatalities, but much better than the German average, which is weighed down by Eschede. (While people stereotype China as shoddy, nobody so stereotypes Germany despite the maintenance problems that led to the Eschede accident.)

I bring up China’s positive record for two reasons. First, because it is an example of how reality does not conform to popular stereotypes. Both within China and in the developed world, people believe China makes defective products, cheap in every sense of the term, and compromises safety; the reality is that, while that is true of China’s general environmental policy, it is not true of its rail network. And second, China does not have buff strength requirements for trains at all; like Japan, it focuses on collision avoidance, rather than on survivability.

The importance of the approaches used in Japan and on China’s high-speed rail network is that it provides safety on a systemwide level. By this I do not mean that it encourages a mode shift away from cars, where fatality rates are measured in 1 per hundreds of millions of passenger-km and not per tens of billions. Rather, I mean that the entire rail network is easier to run safely when the trains are lighter.

It is difficult to find exact formulas for the dependence of maintenance costs on train weight. A discussion on Skyscraper City, sourced to Bombardier, claims track wear grows as the cube of axle load. One experiment on the subject, at low speeds and low-to-moderate axle loads, finds a linear relationship in both axle load and speed. A larger study finds a relationship with exponents of 3-5 in both dynamic axle load and speed. The upshot is that at equal maintenance cost, lighter trains can be run faster, or, at equal speed, lighter trains make it easier to maintain the tracks.

The other issue is reliability. As I explained on Twitter, the same policies that promote greater safety also make the system more reliable, with fewer equipment failures, derailments, and slowdowns. On the LIRR, the heavy diesel locomotives have a mean distance between failures of 20,000-30,000 km, and the medium-weight EMUs 450,000 (see PDF-pp. 21-22 here). The EMUs that run on the LIRR (and on Metro-North), while heavier than they should be because of FRA requirements, are nonetheless pretty good rolling stock. But in Tokyo, one rolling stock manufacturer claims a mean distance between failures of 1.5 million km. While within Japan, the media responds to fatal accidents by questioning whether the railroads prioritize the timetable over safety, the reality is that the overarching focus on reliability that leads to low maintenance costs and high punctuality also provides safety.

In the US, especially outside the EMUs on the LIRR and Metro-North, the situation is the exact opposite. The mean distance between failures for the LIRR’s diesel locomotives is not unusually low: on the MBTA, the average is about 5,000 km, and even on the newest locomotives it’s only about 20,000 (State of the Commuter Rail System, PDF-pp. 8-9). The MBTA commuter rail system interacts with freight trains that hit high platforms if the boxcars’ doors are left open, which can happen if vandals or train hoppers open the doors; as far as I can tell, the oversize freight on the MBTA that prevents easy installation of high platforms systemwide is not actually oversize, but instead veers from the usual loading gauge due to such sloppiness.

Of course, given a fixed state of the infrastructure and the rolling stock, spending more money leads to more safety. This is why Christie’s budget cuts are important to publicize. Within each system, there are real tradeoffs between cost control and safety; to Christie, keeping taxes low is more important than smooth rail operations, and insofar as it is possible to attribute political blame for such low-probability events as fatal train accidents, Christie’s policies may be a contributing factor. My contention here is different: when choosing a regulatory regime and an overarching set of operating practices, any choice that centers high performance and high reliability at the expense of tradition will necessarily be safer. The US rail community has a collective choice between keeping doing what it’s doing and getting the same result, and transitioning operating practices to be closer to the positive results obtained in Japan; on safety, there is no tradeoff.


  1. johndmuller

    Following the Hoboken crash, all the occupants of the lead car, which bore the brunt of it, were safely evacuated, including the operator, as far as I know without the need for any substantial special measures such as the “Jaws of Life” or cutting into the car with power tools or torches – only things like kicking out windows, etc. Perhaps there was some minor amount of that sort of thing, but nothing major enough to come to the attention of the swarming reporters who were hungry for newsy material like that. The passenger injuries were presumably mostly due to people being thrown around at impact (exacerbated by those already standing up to get off). At the same time, substantial damage accrued to the station as the train apparently took out the bumper block and at least 1 pillar supporting some of the lightweight-looking canopies which serve to enclose what seems to have originally been an open air train array of boarding platforms. The train may have further impacted the once outer wall (masonry, perhaps with steel) of the terminal building itself and possibly caused some damage there as well (reports have been somewhat vague/contradictory about that).

    All in all it would seem that the train did the job that the FRA seems to have had in mind when they drew up the specs. The fact that there was no fire or electrocutions and only the not to be minimized single fatality from the platform are also aspects that may reflect well upon and relieve some concerns about the safety of the diesel push-pull system in use. It surprised me that the engineer, being in such an exposed position was largely unhurt despite what must have been close encounters with the bumper block and the pillar(s) and whatever else.

    I guess one could wonder if less armor would be just as effective or perhaps even better (at least for the station structures), and perhaps more economical, but I suppose that the passengers on this train should be grateful to the FRA, whether they know it or not.

    • Alon Levy

      I reject the premise that safety is based exclusively on whether the passenger space in the lead car was compromised. Safety has to be evaluated on a systemwide basis; if the train is so heavy that it plows into a bumper with greater force, takes longer to stop, mows more people on the platform, and destroys more of the support of the station roof, this should be taken into account.

  2. F-Line to Dudley

    RE: freight clearance routes and how that factors into this calculation…

    NJT, including the NJT-operated Metro North Port Jervis Line, has far and away the highest number and highest percentage of stops on federally protected freight clearance routes of any passenger carrier operating in Northeastern high-platform territory. They also have highest number of such stops with no space for building freight passing tracks away from the platforms, and heaviest overall freight traffic on those designated routes because it’s 100% Class I traffic from bigtime Norfolk Southern and CSX. Nearly all of non-electric Hoboken Division territory is affected. They are the system where this is going to have the biggest tangible impact on costs, reliability, and safety. Perhaps the only one where these considerations end up larger than a budget rounding error.

    Present-day MBTA isn’t a great reference because of relatively small number of affected stops, smaller number that don’t have plausible reconfiguration options for passing tracks, and divergent freight traffic levels at the affected stops. Right now it’s only 20 total stops sharing clearance-route freight tracks on 5 lines vs. 135 total full-time stops on 13 lines systemwide. Only half of those 20 stops have anything resembling moderate-or-higher freight traffic. And only 8 of those stops confined to just 2 lines (outer-half Haverhill and inner-half Franklin Lines) have space constraints offering no plausible non-destructive options for reconfig with passing tracks, and are consigned to using the retractable mini-high clearance accommodations more or less permanently. All other presently impacted T stops have straightforward renovations or do-no-harm relocation/re-spacing options for traffic-separated full-highs, and it only requires a moderate-size funding wad to churn through them all with due diligence. Finish the due diligence mods and the count is reduced to a < 5% system outlier.

    The Camden and Brunswick Lines make MARC #2 to NJT on % of system impacted by freight clearances, but MARC's a very small overall system outside the NEC-running Penn Line. SEPTA is only affected to any significant degree on the Fox Chase and outer-half West Trenton Lines. East-of-Hudson Metro North and all of LIRR, ConnDOT, and future built-out RIDOT intrastate service are 100% unaffected. Amtrak high-platform territory (i.e. D.C. Union-north, Pittsburgh- and Niagra Falls-east) only has non-bypassable permanent impacts on Downeaster stops Haverhill-north, Vermonter stops Brattleboro-north, and Adirondack/Ethan Allen Express stops Ft. Edward-north. Once the huge backlog of modifiable stations can be tamed on all of these railroads, NJT (and to lesser degree the MARC branches) becomes a category of its own starkly different from all its peers. Aside from the mechanics of future conversion of Virginia Railway Express + Amtrak Virginia NE Regionals from 8-inch boarding to 48-inch for platform hegemony with the rest of the Northeast, this is unlikely to manifest itself anywhere else. Midwest/West passenger roads are simply not likely to consider ditching 8-inch platforms for full-highs in the first place unless they can guarantee the route(s) under consideration can be designed out-of-box with clean traffic separation at all stops under the fed-protected freight clearances umbrella, without need to invite fresh installs of the mini-high kludge in constrained areas. The mini-high kludge won't spread beyond the legacy Northeast ADA retrofits that are out of better options.

    • Alon Levy

      A lot of this can be prevented by requiring freight railroads to keep the boxcars locked. I’m told that on the Worcester Line, there’s only about 1 actually oversize freight train every month.

      How much freight is there on the Erie lines nowadays? CSX’s main line is the West Shore Line, which is probably a lost cause for passenger rail anyway.

      • F-Line to Dudley

        Late to reply, but here’s the skinny. . .

        — East-of-Framingham had its clearance exemption waived when the big deal was struck to relocate CSX out of Beacon Park. I think official expiration date is 2018 when the last Beacon Park customer’s non-renewed contract expires. T is free to build full-highs all points east to Allston, where freights post- BP closure have shrunk from 28 per day to 2. And possibly 0 in couple years, because after the Allston customer is gone CSX is free to cut a haulage deal for its Everett Terminal fresh produce carloads to have Pan Am–who also serve the Terminal daily via the Lowell Line–tack CSX’s carloads onto their job and deliver to CSX’s doorstep in Worcester for a little extra cash while CSX saves money not running.

        — Double-stack territory extends east of Worcester to Westborough @ the Mass Pike/I-495 interchange. Shipping-cube intermodal goes to trucks in Worcester, liquids and loose aggregate to truck in Westborough. Framingham, however, does still see daily oversize loads because it is the general freight classification yard for all of Eastern MA. Everything miscellaneous coming into or out of region gets sorted there before heading out points N-S-E-W on other locals. Including the stuff that heads right back to Grafton/Worcester for the P&W, Pan Am, and Grafton & Upton RR interchanges. Sorting requires lots of yard tracks to shunt cars into blocks, and Framingham is the only place on the mainline in Worcester County with the acreage to do it. It is primarily those 3 RR interchanges Worcester-Grafton that get the oversize loads sorted in Framingham.

        — Note that Framingham activity does not prevent full-high installs on the 4 outer Worcester Line intermediate stops, as all of those 2000-02 construction stations were pre-designed to have their platforms shifted back next to instead of in front of the overhead ped ramps so a center passing track can get added. T just has to get their big ADA backlog tamed before it has bandwidth to fuss with these.

        — The locals out of Framingham that fan out on the clearance routes to Framingham-Walpole-Mansfield, Walpole-Readville, Manfield-Attleboro, and Attleboro-Middleboro are the ones that only have trace over-wide carloads. Not an issue with the NEC because Attleboro’s quad-track and Mansfield will be tripled/quadded before they get full-highs. Not an issue with Foxboro/Gillette Stadium station because full-time service would install a full-high + passing track. Not an issue Walpole-south on the Franklin Line because it isn’t a clearance route. But the 6 intermediate stops on the upper Franklin Line are mini-high forever because of pinched ROW land and problematic embankments. Those are the only unsolvables on the southside, just like 3-4 Andover and Haverhill stops on the Haverhill Line are the only unsolvables up north. I guess if the North-South Rail Link ever gets built Haverhill and Franklin end up a natural matching pair because they’re the literal only schedules on the system that’ll have to flip the door traps. No issue for any rolling stock because traps are standard equipment on EMU’s .

        9 or 10 stops *partially* dinging just 2 lines is a total non-issue for the system, not worth giving second thought for completism OCD because none of the stops in question are massive enough ridership to cause dwell problems. Those schedules are still decided majority level-boarding stops.

        NJT is the East Coast’s true buzzkill. Norfolk Southern’s eastern hubs where all traffic diverges are Harrisburg and Binghamton, and distributes like this:

        — Mid-Atlantic traffic stuff skirts any SEPTA overlap via the parallel Harrisburg Line, and the monster traffic to PANNY skirts *most* of NJT Newark Div. by the Lehigh Line paralleling the Raritan Valley Line. They have 2 full-highs w/ gauntlet tracks on the RVL overlap, so if any of Newark Div. is unsolvable it’s < 5 stations…and possibly zero.

        — Binghamton's the triple-junction where Buffalo + Albany/New England traffic + Harrisburg traffic meet, and their competing Albany-PANNY route to CSX's nutso-trafficked River Line is the NJT Main Line/Port Jervis. Total unmitigated lost cause on full-highs with nearly all stops because volumes are exploding and passing room isn't available.

        — Both Main Line flanks are affected because west flank is where the branch to the PANNY ports diverges, Bergen County Line is where the interchange to biggish Class II carrier NY, Susquehanna & Western (NYSW) is.

        — Montclair-Boonton west of Wayne gets moderate secondary traffic because of the interchange with a second disconnected flank of NYSW.

        — Future expansion projects of varying degrees of upside have similar issues. Lackawanna Cut-off has a M-B overlap. Passaic-Bergen (half-hearted DMU proposal) has an NYSW and Main Line overlap. West Shore, if it isn't already infeasible with CSX River Line traffic, probably can't build any stations without retractable minis. Only new ones that can be done without flipping a single door trap en route are in Newark Div.: Pascack Valley to Phillipsburg and West Trenton where there's plenty of room for passers.

        Gladstone Branch, Morristown Line, Pascack Valley Line, and Meadowlands spur are free-and-clear, but that's a rather insignificant collection of ridership share from Hoboken Div.

        • F-Line to Dudley

          Gah…typos. Last bullet is “Raritan Valley” to Phillipsburg, not Pascack. And “PANYNJ”.

          Also forgot to mention on the T that Framingham station-proper is fine because the diminished freight traffic can go around the wye to stay off the platforms. If the Springfield-Boston Inland Route happens, Framingham goes level automatically as an Amtrak requirement for routing any Springfield NE Regionals to Boston.

        • Alon Levy

          Maybe I’m missing something, but Morristown + Gladstone are the majority of Hoboken Division ridership, no? They have way more ridership than the Erie Lines, and about half the trains go to Hoboken rather than Midtown Direct…

          • Adirondacker12800

            NJTransit hides quarterly ridership reports somewhere on their website. I’m not going to go rummage for them or do the arithmetic again. If I remember correctly the NEC and North Jersey Coast are about half the total ridership, Montclair-Boonton, Gladstone and Morristown are about the third and anything left is the other lines. With about half of that remainder being on the Raritan Valley line. IIRC.

          • F-Line to Dudley

            Yeah. Current Hoboken electric territory is fine, so the lines/stations where they’re flipping the door traps are places where the crowding isn’t so extreme that they’ll have to worry about dwell times becoming a problem from a low platform. The only consideration with M&E electric territory is this talk from their last fleet plan presentation of going to an EMU-heavier fleet distribution with the option orders on the Arrow-replacement MultiLevel EMU’s. Mainly because the sloppy mixed Arrow + ALP-46 assignments on same schedules wastes way too many coaches’ daily service hours with out-of-service cycling. Segregating all-electric schedules to be 100% this stock or 100% that stock cuts out that waste and puts more total cars in constant circulation.

            In that case the M&E + Gladstone are ideal candidates to get their ALP-46’s purged for all- MLV EMU’s because their diesel dual-mode schedules are so diffuse and light on required equipment. But it leaves NJT very hard-up for EMU-capable yard and heavy-repair capacity. Port Morris Yard right past Lake Hopatcong is the only very large and underutilized in-house acreage that’s easy-grab for a full-service facility without NIMBY interference, so they would likely extend the wires Dover-LH and increase schedules through the wide-clearance M-B platforms as an ops–not ridership–necessity. Possibly with later motivation to close the Montclair-Dover diesel gap on the M-B through those forever-lows west of Wayne. Not any sort of fait accompli, but the PM Yard considerations are their path of least resistance and lowest cost for flushing the Hoboken Div. electric schedules full of EMU’s where the EMU’s most need to go.

            Very negligible consideration for the forever-low platforms out there, but it underscores that NJT Hoboken Div. is singularly unlucky for 48-inch territory at having this be a permanent factor.

            — MBTA got very lucky as only 6-8 out of 34 total stops scheduled inside wide-clearance territory will ever be hard or impossible solves.

            — SEPTA got very lucky with only 3 fully-solvable West Trenton and 1 Norristown stops that even touch a clearance route.

            — MARC got lucky with only the insignificant-zit Brunswick Line, and maybe 3-5 total Camden Line stops that can’t be solved.

            — Amtrak got very lucky with the Downeaster being the only route with >3 current or planned daily frequencies affected. The Adirondack and Ethan Allen Express Ft. Edward, NY -north, Vermonter Brattleboro-north, and EAE expansion territory on VT’s Western Corridor are the only others affected in 48-inch territory. Even PennDOT’s Harrisburg-Pittsburgh corridor studies checked out for 100% level boarding, despite the Pennsylvanian using Norfolk Southern’s single-busiest freight line the whole way west of Harrisburg.

            — Should State of Virginia get officially re-designated from 8-inch to 48-inch territory for continuity’s sake, all 38 of the state’s Virginia Railway Express and Amtrak stations–each and every one on a major CSX or Norfolk Southern clearance route–have fully-feasible solves. Megaproject cost to convert a whole state, but never in doubt.

            That’s one hell of a short straw Hoboken Div. somehow managed to draw on pure bad luck. May not be a big drag given that NJT dodged a bullet on lines with any major potential for platform dwell problems, but bizarre all the same that chance sacked them with three-quarters of all of 48-inch territory’s unsolvable retrofits.

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