You might think that all cycling advocates would support bicycle lanes. You’d be wrong. Some cyclists oppose bike lanes on the grounds that they protect only from rear-end collisions (which are rare), and increase the likelihood of collisions at intersections (which are more common). The research data is a bit conflicting. Here at Bicycle Universe we generally support bicycle lanes because:

They make cycling feel safer. The surveys always show that #1 reason why people say they don’t bike is that they feel it’s too dangerous, and the #1 thing that would make them feel safer is more bike lanes. Even if bike lanes don’t help, it’s unlikely that they hurt. Some research shows that streets with and without bike lanes are about the same risk for cyclists. In that case, there’s no harm in installing the lanes, especially if they encourage more people to bike. Bike lanes mean more cyclists. Cities that install bike lanes see an increase in the number of cyclists. (source) Bike lanes keep cyclists off sidewalks. Riding on the sidewalk drops when bike lanes are available. Riding on the sidewalk is dangerous to pedestrians, and actually dangerous even to cyclists because they’re vulnerable to getting hit by turning cars when coming off the sidewalk to cross the street. Other countries have them. Other countries with higher rates of cycling (and lower rates of cyclist injuries) employ bike lanes.

Some of the research into the safety of bike lanes is listed below.

Bike Lanes: Pros & Cons

Research supporting the safety of bike lanes

Bicycle Quarterly. Cites European data which shows that separated bike lanes (with a physical barrier) cut the accident risk in half on high-speed roads (45 mph). American Journal of Public Health, 2012. Bike lanes cut injury risk by 50%, dedicated bike lanes cut it by 90%. John Forester challenged its conclusions, saying in part: “In the much more impressive cycle-track issue, the authors proclaimed enormous crash reduction without informing the readers [that they studied only a single installation which] was not along a typical city street but [was] the only situation in which a plain cycle track could possibly be safe, a place without crossing or turning movements by motorists, cyclists, or pedestrians. The authors refer to the forty-year-old cycle-track controversy as if they had studied it, but clearly, they don’t understand it.” Forrester notes the absence of on-street parking is correlated with safety for cyclists. University of Texas study, 2006. Study shows improved safety for motorists when bike lanes exist because drivers passing cyclists on roads without bike lanes veer farther left into the next lane of traffic. It also found that bike lanes promote safety for cyclists since bikers in bike lanes don’t hug the curb as much as those on unmarked streets. Moritz’ 1996 study gives strong evidence that streets with bike lanes are safer than those without. The community development department of Cambridge, MA has evidence about the safety of bike lanes. Bicycle Lanes vs. Wide Outside Curb lanes. Study by the U.S. Dept. of Transportation. (And here’s a critique of that study by John Forrester.) Mike Dahmus did a small sampling to see how closely cars passed him on Shoal Creek Blvd. in Austin, Texas, when there was no bike lane and then again after the bike lane was stripped. He observed that cars kept a greater distance from him on average when there was no bike lane, but that without a bike lane cars would occasionally pass much closer than when the bike lane was there. His conclusion was that the bike lane provides a measure of safety because with the bike lane cars are more likely to maintain a minimum safe distance from cyclists. Texas Transportation Instititute, 2000 (PDF). Study found that the wider the lane, the faster drivers drive. Bicycle Coalition of Philadelphia. Sidewalk riding dropped from 19.8% on streets with no bike lane to 8.6% on streets with a bike lane to 2.4% on streets with a buffered bike lane.

Mixed pro/con

Listening to Bike Lanes by Jeffrey Hiles strikes a balance between those who support and those who oppose bike lanes. Lots of good data here. BicyclingInfo.org has a balanced article Pros and Cons of Bike Lanes by Alan Wachtel.

Opposed to bike lanes

Bicycle Quarterly. Cites European data which shows that painted bike lanes offer no benefit on most urban roads (30-45mph), and are much more dangerous on low-speed roads (12/20mph) than no bike lane. Critique of US DoT study on bike lanes & wide outside curb lanes, by John Forrester

Related resources & ideas

Bike lane design guide (PDF) by the US DoT “Sharrows” are “shared-lane arrows” painted onto the street to show motorists and cyclists that they’re supposed to share the lane. They’re being promoted as an alternative to bike lanes, especially on roadways where there isn’t enough space for a dedicated bike lane. Alta Planning conducted a detailed study of sharrows (PDF).

Pros and Cons of Bike Lanes

by Mike Dahmus,

There are no good studies proving that bike lanes or wide curb lanes are better than the other. ALL theories you hear on which one is better are resting on somebody’s opinion. [Updated, Feb. 2007: A few months ago, a study did come out which claimed to show a non-trivial safety enhancement for marked bike lanes vs. wide curb lanes.] I’m one of the people who thinks we overprescribe bike lanes, but it bugs me that so many Forsterites are so hostile to them in general. Both bike lanes and wide curb lanes have their place. I’m operating under the assumption that we’re comparing bike lanes to wide curb lanes; not narrow curb lanes. The theory that we can reengineer the 98% of Austin that needs it to a grid pattern like Hyde Park where we don’t need EITHER facility is just ludicrous. My general feeling on when bike lanes are appropriate: Where there are lots of inexperienced bicyclists Where speed differential is fairly high Where volume of bicyclists is very high My general feeling on when wide curb lanes are appropriate: Where speed differential is lower Where bicycle volume (all types) is moderate to low Where not to put bike lanes: Low-speed or congested roadways where turning volume is very high Residential streets (NOTE: DESPITE NEIGHBORHOOD MISREPRESENTATIONS, “RESIDENTIAL STREET” IS A CATEGORY OF ROADWAY SEVERAL LEVELS BELOW SHOAL CREEK BOULEVARD). Where they can’t be swept or otherwise maintained Where you can’t commit to “no parking”. Things I believe that are PROs for bike lanes: Bike lanes attract new cyclists; wide curb lanes do not. I think this is self-evident. Patrick agreed, and so do most people who actually work in the field (not the people who commute and criticize; but the people who are paid to try to increase cycling in their particular city). No amount of education so far has been able to match up against the bike lane stripe as a way to get people out on their bikes. Of course, this may be a good thing if you think we don’t need more uneducated cyclists out there. You can’t attract new cyclists to a road like Jollyville without a bike lane stripe. Period. The automobile traffic moves too fast. A wide curb lane simply doesn’t provide the space that new cyclists think they need in a way which makes sense to them, coming from the world of the automobile. (We don’t make the right-hand lane up a hill twice as wide so trucks can pull to the side; we stripe another lane). If you accept riding on shoulders on 360, you should accept riding in bike lanes on Jollyville. The argumentative convulsions some Forsterites go through to defend shoulders from the same logic they use against bike lanes are breathtaking. (They do this, I think, because they know that even most Forsterites don’t want to share a lane at 65; the same anti-bike-lane reasoning with a few exceptions would logically apply to shoulder-riding). Most cyclists for whom bike facilities are built are not the expert cyclists that you and I might be. They are instead the novice cyclist that I used to be (and presumably you used to be). Even on low-speed roadways, utility for the population AS A WHOLE sometimes demands the channelization of low-speed traffic. For instance, Speedway and Duval north of UT – car speeds are 25-30; bike speeds are 10; this isn’t normally enough speed differential to justify separation, but the volumes of cars and bikes are both high, and the corridor’s thoroughput for both cars AND bikes is thus improved by partial separation of the modes. (this is from the link I gave a few days ago) – it is possible to have a better average passing distance on a roadway with a wide curb lane, but still have a better overall level of safety in passing distance with a bike lane. Whether this happens in practice is debatable – but it is a fact that you shouldn’t use “average passing distance” to compare the facilities. The idea (stolen from a semi-Forsterite) that we can easily get roads restriped with wide curb lanes is in reality not true. If you want space for bikes to be taken from car lanes, it generally has to be a bike lane. (I don’t know why this is, but it seems to be true, although Austin has an exception or two here). CONS for bike lanes Car drivers do tend to think you need to stay in the bike lane (even when obstructed, unsafe, whatever – they usually can’t see the obstruction). Also, car drivers often think you should only ride on roads that have bike lanes. This problem exists with wide curb lanes too, by the way. Bike lanes are theoretically more obstructed than wide curb lanes. I don’t believe this to be true, but most people do, so I’m listing it here. For instance, Bull Creek doesn’t seem any less obstructed north of 45th where there are wide curb lanes. In Austin, at least, BOTH facilities need vast amounts of sweeping which they’re just not getting. Sometimes cyclists will stay in a bike lane when they need to leave it due to an obstruction or intersection approach. This is a sign of bad bike lane design in most cases and can be overcome, but is hard to get right, judging from how often it’s done wrong. Sometimes cyclists will stay in a bike lane when they should be leaving it to turn (the “turn left out of the far right lane” phenomenon). The problem here is that I see this happen on wide curb lanes fairly often as well. The only solution here is heavy enforcement. Bike lanes supposedly encourage wrong-way cycling. (Whatever happened to painting arrows, by the way? Jollyville didn’t get them…) – again, I see this often with wide curb lanes too. Heavy enforcement and more arrows.

Questioning the safety of bicycle lanes

by Fred Meredith,

You may FEEL safer, but it may be a false sense of security. The only thing that is going to actually make you safer on those streets is how you and the other road users behave…. If the bike lane is painted to the intersection, are you going to stay in it if you go straight across the intersection? What should the car turning at that intersection do? Should he/she come over into the bike lane to make the turn? Do they know that? Are you going to stay in the bike lane if it is right next to parked cars [any one of which could open its door in your path]? If cars are parked on the left side of a one-way street and there is a bike lane on the left side, are there special considerations you should keep in mind? Why is the bike lane any safer than being out in the middle of the traffic lane? There are lots of other lanes for the rest of the road users, why shouldn’t you have one? If you feel unsafe in a traffic lane, then maybe you need more experience/practice/or something. Maybe less paranoia.

by Jeffrey Thorne,

I have to question some of the statements supporting bike lanes from the research above.

“encourage bicyclists to ride in the correct direction of travel”

That doesn’t match my observations here in Austin. Judging by the number of riders I see riding the bike lanes against traffic flow, I’d say they encourage that behavior instead. I don’t see much riding against traffic except in bike lanes. I have to wonder about the “national study” concluding otherwise. According to Jeffrey Hiles’ Listening to Bike Lanes (see below), more cyclists ride the wrong way on streets with bike lanes than on those without.

“signal motorists that cyclists have a right to the road”

That is, they signal that bikes belong in bike lanes, which some would take to mean ONLY in bike lanes, which is a false message for motorists and cyclists alike.

“remind motorists to look for cyclists when turning”

In my experience and in the conclusions of several studies, bike lanes may actually increase the incidence of motorists hitting cyclists while turning in front of them. This seems to be because the motorist who normally would turn right from the right edge of the road, not cutting off the cyclist’s path (the cyclist would be behind or in front of the turning car), is encouraged by the bike lane stripe to make the turn from a farther left position, cutting off the cyclist’s path. I do support bike lanes as a tool for solving traffic problems where problems are occurring. Usually, I see bike lanes being established where riding was safe and enjoyable already, and in those places they are at best a waste of paint and at worst creating dangers that weren’t present before.

from Jeffrey Hiles’ Listening to Bike Lanes

Studies of bicyclists’ behavior point to one overriding rule: The more options cyclists have, the more options they take. This is true whether or not those options are officially sanctioned. The side of the street on which bicyclists ride, for example, is influenced by the kind of space they have in which to ride. Thom and Clayton (1992a) observed bicyclists riding at mostly busy intersections with standard 12-foot lanes and speed limits mostly either 50 or 60 kph (31 or 37 mph). A full 97.6 percent of the cyclists rode on the side of the street with the flow of traffic (p. 97). On most of the streets at the seven intersections studied, bicyclists would have had to ride close to on-coming traffic if they had chosen the other side of the street. The picture changes where bicyclists have more room. A study of bicyclists on nine streets with striped bike lanes (Cycecki, Perry, & Frangos, 1993) found that 22 percent of the cyclists who rode on the streets chose to ride facing the motor traffic on their side of the street. On one street the bike lane was marked with four arrows per mile “to show clearly that bicyclists must ride with traffic.” Apparently the arrows did not deter wrong-way riding as much as the extra space encouraged it; 23 percent still rode facing traffic. On another bike-laned street, 39 percent cycled against the flow (pp. 29, 31).

from Tom Wald,

If you’ve biked on west 29th St between Rio Grande and Shoal Crest (between Guadalupe St and Lamar Blvd), you probably recognize a case where the painting of bike lanes is highly questionable. On this stretch of road, from the center line to the curb is about 14 feet. (Not so incidentally, 14 feet is the maximum lane width for which Texas State Law *explicitly* allows a bicyclist to use the entire lane). However, there are currently bike lanes marked on this stretch of road. These bike lanes measure about two to four feet wide, if my spatial memory is correct. My impression is that some motorists get fairly frustrated when I ride outside of the marked bike lane on this road, as is evidenced by their aggressive driving, creating unsafe situations for all involved, and horn signals. I don’t really fit inside the bike lane — in some places, I think any of my bikes are too wide for the lane. Of the three choices — bike lane, sharrows, and no markings — having marked bike lanes easily takes last place. If sharrows were used, I’d like to see them centered somewhere between 40-50% from the center line so that motorists don’t get any impression that it’s reasonable to pass. Perhaps though, in 2007, no markings is the best choice.

Supporting Bike Lanes

Mike Dahmus,

Most of the people who argue that bike lanes are almost always bad tend to be in one of these groups (or combinations thereof): focused with laser-sharp precision on the needs of current (experienced) transportational cyclists (i.e. don’t think or care about kids, novices, elderly) – tend to be people who live in areas where cycling just tends to happen by itself and doesn’t need promotion or encouragement. inexperienced with suburban cycling conditions (i.e. why would you ever need a bike lane or marked shoulder if roads are laid out in a grid pattern with design speeds of 30 mph) – tend to be disproportionately European, some Amercan adherents among Forsterites mainly in the northeast or midwest United States – areas which haven’t seen much growth since the 1960s or so. IE – these are people who never have to ride on roads like Jollyville to get where they want to go. careless about the needs of the city to ensure good traffic flow for all users of a corridor – i.e. sometimes the bike lane exists to increase the likelihood that motorists can maintain some reasonable level of speed, and this isn’t necessarily a bad thing. IE, these are people who think the city shouldn’t care that automobile traffic would often and suddenly be restricted to 10 mph or so on any given street since some motorists don’t effectively know how to pass cyclists without the help of a stripe. They also tend to neglect statistical thinking in their arguments – focusing, for instance, on the average passing distance they get from motorists in wide curb lanes vs bike lanes, rather than looking deeper to the 10th percentile case. Those of us in the real world note that many Shoal Creek corridor users are very young or very old, and that it tends to attract novice cyclists of all ages (me, for instance). It, while theoretically a low-speed corridor, has an apparent design speed of 40 mph or so, and serves as a transportation spine which can be an alternate for Burnet Road and Mopac for cyclists (improving conditions for cyclists and drivers if it succeeds in attracting most cyclists away from those two corridors). It also functions as a minor arterial itself (even though bogusly reclassified as a collector) and thus needs to worry about flow of cars in addition to bikes.