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I am trying to find a study, which I've read sometime ago, which compared the cost/Km of a motorway vs a cycle lane.

I don't know the exact picture I've seen but I have the idea the study was from Canada and the conclusion was 1 km of motorway costs the same as 300 km of cycle lane.

If someone can inform where I can get again study, many thanks. If not possible I will appreciate some other studies about the same subject.

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    You'd have to define your criteria better. How wide are the lanes? What paving material is used? Do they need to have comparable persons/per hour or some such? – Daniel R Hicks Mar 2 at 1:54
  • Does the bike line need to be able to transport Goods? – mattnz Mar 2 at 7:31
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    This is a too general question. If you refer to a specific country, we may be able to pinpoint an answer. Otherwise, the only possible estimate is that bike traffic is much lighter than road transit (so the pavement needs much less support below) and that wide cycle lane are (optimistically) roughly half as wide as a 2-lane roads. So you can think that you need 10 times less support (10cm vs 1m of dug trench to prepare for the road) and 2 times less wide. Taking into account that the cost of digging are volumetric, they may scale with the square, so a car road costs 10*10*2 = 200 times – EarlGrey Mar 2 at 8:21
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    Related - the cost to society of using the motorway (cars in general actually) vs a bicycle (and walking): sciencedirect.com/science/article/abs/pii/S0921800918308097 - don't forget you can use Sci-Hub to get access to papers – thosphor Mar 2 at 9:40
  • I am not sure it will be on this blog but there is a good chance that you will find either the study, a link to it or an alternative study on this site: aviewfromthecyclepath.com/2020/08 (random date, use the blog search for the best results.) – Willeke Mar 4 at 19:02
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https://activelivingresearch.org/sites/activelivingresearch.org/files/Dill_Bicycle_Facility_Cost_June2013.pdf

For example, the City of Portland calculated that the city’s entire bicycle network, consisting of over 300 miles of bikeways would cost $60 million to replace (2008 dollars), whereas the same investment would yield just one mile of a four-lane urban freeway.

...bicycle lanes can often be added to streets as part of planned maintenance or re-striping projects at a cost of $1 - $5 per foot (excluding right of way acquisition and engineering costs). Bicycle boulevards... generally cost between $9.50 and $27.20 per foot.

Assume values are US Dollars from 2008. Portland is fairly close to Canada, and the 300:1 ratio is mentioned, fortunately the units cancel out.

The only niggle I can see is that a 4 lane freeway has four lanes, whereas the bike lane's width is not stated. So it could be 75:1 ratio, or 1200:1 if the boulevard could take 16 bikes side by side.

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    I'm afraid this quote compares incomparable works. It compares painting a bicycle lane on an existing road with building a new road. – Pere Mar 3 at 9:34
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    @Pere agreed - but it seems to be the report OP was quoting originally. Bike lane costs are hard to compare because of vested interests skewing things, both toward and away from the bike lane. – Criggie Mar 3 at 11:06
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https://www.seattletimes.com/seattle-news/politics/12-million-per-mile-for-a-bike-lane-that-should-trigger-a-civic-heart-attack/

Rather infamously, a bike lane in downtown Seattle recently cost $12 million for 1 mile! In any study, it's important to determine what was included in the costing. Freeways/motorways typically do not include intersections and signaling. Bike lanes typically do not include lighting but may have more or less involved side barriers and traffic light signalling systems included in their cost. Land acquisition costs are often the biggest cost component, but are not counted in calculations like that above for rebuilding Portland's lanes.

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    Good point - a 10 litre can of paint might be $100, enough for a 10 km stripe, but a fancy bike lane with potplants could cost that much per metre. They aren't equal at all. – Criggie Mar 2 at 6:42
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    Sometimes people with an agenda will give misleading information and it can be hard to determine that when reading one article. For example in my city there was an uproar about an expensive cycle lane (they all seem expensive when you don't want them at all of course). It turned out the quoted cost included digging up and replacing the hundred year old water and sewage mains which was a project the city was doing anyway. Not a single person who complained to me about how much money was being spent on cyclists knew about the drain works and they didn't care when I told them. – Eric Nolan Mar 2 at 15:04
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This answer explores the theoretical cost differences between building equivalent roads and bike lanes. It does not put any dollars on the costs as these include much more than the road / bike lane itself (rails, markings, signs, lights, noise protection, etc.) that depend heavily on the exact location.


First, we need to ensure that the bike lane and the motorway are actually comparable. I'll take the throughput for this, the count of vehicles passing any point within a given time span:

  • Assume that cars drive 100 km/h and keep a safety distance of 30m. With the length of a car (5m), we get a rate of 100000/35 = 2900 cars per hour.

  • Assume that bikes drive 20 km/h and keep a safety distance of 6m. With the length of a bike (2m), we get a rate of 20000/8 = 2500 bikes per hour.

Ok, so a single lane of 100 km/h motorway has about the same throughput as a single lane of bike path. However, bikes are not as wide as cars, and that is one point where you can get significant cost reductions: A 100 km/h road needs to allocate at least 3.5m width per lane (2.5m truck plus safety distances), a cycle path may get away with 1.5m (0.5m bike plus safety distances). I.e. the road consumes about twice the space that the bike lane consumes.

Another factor is the robustness of the road. I cannot give numbers on this, but 2t cars to 40t trucks at 100 km/h put a lot more stress on the road than 100kg cyclists do. The asphalt of the motorway needs to be much thicker and well-constructed than the bike lane to last the same amount of years/vehicles. However, road construction vehicles are heavy as well, and the bike lane needs to survive its own construction. As such, there is a lower limit on the robustness of a bike lane that has nothing to do with the traffic it's intended for. Nevertheless, you need significantly less material to construct 1 m^2 of bike path than you need for the same area of motorway.

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    Construction vehicles should not be travelling at motorway speeds, of course - and the damage caused by heavy traffic is quite speed-dependent, so that lower bound is quite a lot less than the motorway loading. – Toby Speight Mar 2 at 20:07
  • @TobySpeight That's pretty much what I said in my last sentence: You need significantly less material per square meter bike path than for a motorway, even though the exact amount for the bike path has nothing to do with the bikes. I just didn't mention the speed as a cause explicitly. – cmaster - reinstate monica Mar 2 at 23:37
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    I wasn't disagreeing - just adding a bit of extra context. Sorry if I appeared to contradict. – Toby Speight Mar 3 at 7:53
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    Robustness and cost of pavement is more dependent on maximum loads than on speed. However, speed constrains geometry, and that makes motorways need for bridges, tunnels, bigger earthworks and so. – Pere Mar 3 at 9:38
  • @Pere That's true. On the other hand, cyclists struggle much more on ascends than cars do. The power to weight ratio is just so much higher for cars, 100kW/2t = 50W/kg for your average SUV, 250W/85kg = 3W/kg for a strong commuter cyclist. As such, a good bike road should be build with a very limited slope. – cmaster - reinstate monica Mar 3 at 10:05
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You will find that studies from different regions will yield different ratios. A Dutch study will have taken place in the country with the highest cycling penetration and most extensive cycling infrastructure in the world, whereas UK or US studies will have taken place in countries where cycling is primarily seen as leisure, and modes of transport other than motor vehicles are often not accommodated at all.

This can lead to differences such as whether or not to take parking into account, or the environmental impact. Bicycles require very little space to park or maneuver, and their operation results in zero emissions. Motor vehicles, on the other hand, often cannot turn without going round the block in urban areas, require 5+ times more space to park, and emit quite a few toxic substances. Additionally, motor vehicles require much more infrastructure to resolve conflicts and keep up (a sense of) safety, such as lights and physical barriers to reduce speed or separate road users.

When comparing studies, take these potential differences into account. Good luck.

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  • In fairness, human-powered bikes result in CO2 emissions :) Electric bikes, less so. – Armand Mar 2 at 14:30
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    Comparing CO2 emissions from people and those from burning fossil fuels (which are likely the source of the electricity) isn't valid. – Eric Nolan Mar 2 at 15:08
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    While a valid comment, this doesn't actually help the OP find a study like they've requested... – DavidW Mar 2 at 18:21
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    @TobySpeight but cars will eventually require parking, and it is expensive. This study calculates that Seattle has spent $117,677 per household in parking. – Davidmh Mar 2 at 20:30
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    @Armand while I know your comment was meant to be glib, it is very unlikely that an electric bicycle will produce less CO2 than a human powered one. Electricity is taken from a grid that is maintained by >0 fossil fuel plants, which produce CO2. The share of CO2 that charging your bike produces depends on your locality. In any case, an electric or man powered bicycle produces orders of magnitude less CO2 than any car. – BlackThorn Mar 2 at 23:34

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