Chart of the Day: Vehicle Weight vs Road Damage Levels

Via Pedal Fort Collins, here’s a simple chart showing the basic relationship between vehicle weight and the amount of “damage” or wear that is caused to the roadway. The relationship is pretty straightforward, but thanks to the magic of gasoline, people often forget to think about the weight disparities on our roads.

Thus the chart, where weights and damage ratios are scaled against the weight of the average car:



Here’s the conclusion from Meg Dunn, the Colorado bike blogger:

It would take 700 trips by bicycle to equal the damage caused by one Smart Car. It would take 17,059 trips by bike to equal the damage caused by an average car. And it would take 364,520 bike trips to equal the damage caused by just one Hummer H2. !!!!!

So let’s talk about this in terms of taxes. For the sake of argument, let’s say that every 1,000 miles traveled in an average sized car equals $1’s worth of damage to the road that will have to come out of City coffers for repair work. A bicyclist would have to travel over 17 million miles to cause the same $1’s worth of damage.  Or another way to look at that, for the $1’s worth of damage that a car does to a road, a bicycle, traveling the same distance on the same road, would perpetrate $0.0005862 worth of damage. That’s about a tenth of a ha’penny.

The “bicyclists don’t pay taxes” argument is one you hear over and over again. Not only is it incorrect, but if road taxes were weighted (see what I did there) to scale in proportion with road wear, bicyclists could pretty much pay for the roads with spare change.

Actually, I’m sure that’s not completely true. Roads do not last forever, even when never used. Entropy is a thing, after all…

But it’s almost completely true. Especially when compared to a garbage truck.

20 thoughts on “Chart of the Day: Vehicle Weight vs Road Damage Levels

  1. John Charles Wilson

    In all fairness, though, isn’t it reasonable to tax bicycles for specialized bicycle infrastructure (protected lanes, paths, etc.) as a separate issue from damage?

    1. Alex CecchiniAlex Cecchini

      Cities don’t tax motorists for their infrastructure. And only a small percent of a city’s lane miles are county or municipal state aid streets, and only a portion of their funding comes from those pots of money funded by state user fees (gas tax, motor vehicle sales tax, registration). So, I think it’s fair to say no, it isn’t reasonable to tax a mode of transportation that is one of the cheapest (personal and public provision) to get around. To that point, there’s an argument that since most transit routes run on city streets and is very local travel, it’s not crazy to say local bus routes should just be free – just like hopping in a car and driving a mile or two to the grocery store.

    2. Sean Hayford OlearySean Hayford Oleary

      One of the greatest beneficiaries of segregated infrastructure is the motoring public. If we took the number of people riding on the Midtown Greenway and put them all on Lake St (or even the 20% who might be willing to ride on Lake St), it would have a significant adverse effect on motorized traffic.

      Specialized bike infrastructure provides a “right-sized” solution for smaller and more vulnerable users.

    3. Adam MillerAdam Miller

      Maybe, but it also may make sense to offer this small subsidy in order to encourage (1) cycling as an alternative mode of transportation or (2) cycling for exercise.

      Also what Alex and Sean said.

    4. Bernie

      To be fair, roads are for transport, not storage. So if we removed all on street parking there would be no need to build specialist infrastructure for bicycles as there would be a nice wide corridor to cycle on. Motor vehicles don’t even come close to paying their fair share.

    5. Rosa

      How do we pay for interstates? Nondrivers pay a lot of income tax, isn’t that the main funder of all those roads nobody not in a motor vehicle is allowed to use? I definitely pay for the road in front of my house even if I “never use it” (though I get deliveries even if I never drove.) I have to pay for the sidewalk even if I never use it too – not to mention having to shovel it.

      If motorists would safely share roads without driving over other people, we wouldn’t need separate infrastructure. I would be TOTALLY up for paying a bicycle tax if we could have a 15-20 mph speed limit on all residential streets to make them accessible to all users. And if road designers would get rid of whatever makes it so unsafe to cross streets that they just put up “No walking” signs at so many intersections (right turn cuts is what it usually looks like.)

  2. Alex CecchiniAlex Cecchini

    We need a post to counter this common urbanist message. The reality is that a road built to handle the extra wear and tear from trucks vs cars, or cars vs bikes, does not cost the same multiplier as the damage. An extra inch or two of pavement depth adds maybe a couple percent to the cost of a project (things like design, curbs, etc are all fixed costs for most projects), and you’ll get a roadway with the same lifespan. It’s why a bike trail doesn’t cost 0.00006 times that of a lane for cars.

    Beyond that, we should also admit that buses are big and heavy and do a lot of damage to roads just like trucks. We need to clearly articulate why a bus with 60 passengers (weighing 30-40,000 pounds) doing a ton more damage to the roadway than 50 cars carrying 1.2 passengers each is a good thing. Yes, the bus is space efficient and more environmentally friendly. But the damage argument still holds. Why the double standard?

    1. Sean Hayford OlearySean Hayford Oleary

      The other good counter is that asphalt in particular has a finite life and a certain amount of maintenance required no matter what. There’s a 20-year-old strip of asphalt between my garage and alley that has virtually never seen any traffic on it, and it’s still in atrocious condition, simply because it’s never been seal-coated, and the heat, cold, and age have eaten away at it.

      (Speaking of which: if anyone knows how to get sealcoat in something smaller than a 5-gallon drum…)

      1. Rosa

        you can probably get a partially used drum by asking on your local listserv or Freecycle, or stop by the Habitat ReStore. Or if you’re going to be in Chaska for some reason the Carver County Environmental Center is likely to have some. Sealcoat is exactly the kind of thing people buy a giant container of and then half sits in the garage waiting to go to toxic waste.

    2. Darren

      I do not have numbers to back myself up so I will not make any assumptions, but 50 cars take up considerably more road space than one bus with 60 people. So even if the per-person road wear is less for private vehicles, they need more road space per person. That requires higher up front capital costs to build the road. It also means lost lost tax revenue due to using land that could be developed for homes and businesses to instead move vehicles.

      In addition to a higher investment in road space for moving vehicles, additional urban land must go toward providing parking for private vehicles (not an issue for bus riders). For surface parking lots, this further erodes tax revenue by consuming land that could have housing, industry, or commercial uses on it.

      So again, I do not have numbers so I do not want to be too confident, but I would argue that even if cars incur lower per-passenger maintenance costs, they require a substantially larger amount of asphalt/concrete per person and present an opportunity cost through lost tax revenue, and the theory amongst urbanists would be that these costs perhaps outweigh the higher wear costs that buses incur.

  3. David MarkleDavid Markle

    It’s easy to see the consequences of high truck traffic on a stretch such as Vandalia between I-94 and University Avenue in St. Paul. (Incidentally a route bicyclists should best avoid.) Problems start showing up very soon after resurfacing.

    Something that I’ve never encountered in print is a comparison of the maintenance costs of roadways built to a higher standard–as in Germany–compared to those in our country. There’s noticeable irregularity and unevenness in even newly laid U.S. roadways compared to those in Germany. And according to common sense, those slight dips and bumps must accelerate the deterioration of both pavements and vehicles.

    At least in Minnesota we’ve minimized or avoided the problems of road wear and safety associated with “double bottoms”–sometimes referred to as autobahn trains in Germany.

  4. David MarkleDavid Markle

    As for the cost of street improvements and amenities for cyclists, including the percentage of area allotted to bicycle lanes, the owners of the property that front the street are the most likely payers. And as business owners they may lose parking. Thus the many objections.

    1. robsk

      David is right about who pays the most. The owners of the property that front the street pay with property taxes. I love sidewalks, but I wish I could move my sidewalk 6 ft. closer to the curb. Can’t do much with the lawn in the public easement, except I have to maintain it and the city gets to choose which trees can grow there.

      How to pay for things?
      Ask Stillwater residents. Bicycle taxes are silly. Are we going to tax pedestrians for using sidewalks? We really should focus on reducing costs and making roads last.

      I’ve seen plenty of streets & sidewalks ruined by lack of activity. Vegetation growing in the cracks and dirt narrowing the shoulders. You might as well say anything that doesn’t cause a measurable amount of damage actually benefits the roads.

  5. Opus the Poet

    I created the fat guy on a heavy bike comparison chart back in the Aughties, only my chart set the starting point at the FGOB as 1 and went to the US DOT GVW limit as 160,000,000 FGOB.

  6. GlowBoy

    The idea of taxing cyclists is as old as cycling itself. It comes up again, usually as a punitive measure, or a way to make cyclists “pay their fair share” or at least to make them have a financial stake in the road system or something, or more often from someone who resents cyclists for various reasons.

    Problem is, the idea doesn’t work. The many studies that have been done on it all find that it costs as much to administer such a program as it would raise.

    Worse, it radically discourages cycling. Only those who are really gung ho about it will pay the tax, and more casual cyclists will not bike because they haven’t bought their permit.

    As for the paying-for-infrastructure or paying-fair-share, it doesn’t make sense on multiple levels: 1. cycling infrastructure is drastically cheaper than car/truck infrastructure, 2. cycling infrastructure already pays for itself in reduced car/truck use of the roads, and benefits car users at least as much as it does cyclists, 3. car use is already subsidized at many times the level of bicycle use, and 4. most cyclists aren’t freeloaders, paying normal income, sales and property taxes (which is actually what pays for most road costs) at similar rates to everyone else. Most are even car owners, paying registration fees and those beloved user fees (gas taxes) on the days they do drive.

    Bottom line, is comes in as a finalist for the Worst Idea Ever prize. The level on which such a program can succeed is if your goal is “sticking it” to cyclists and discourage people from riding. “In fairness” is about the last thing that can be said about it.

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