Bicycle lanes as a means of traffic calming

[Pete Fagerlin]

Making wide roadways narrower by adding a stripe to delineate a bike lane is supposed to slow down traffic.

On the two local streets where that has been done, I haven't seen any change in speed and speeding continues to be an enforcement issue for the local PD.

Does anyone have any experience where adding a bike lane reduced motorist's speeds?

[sbhikes]

I don't have any numbers, but recently they added a bike lane by removing a traffic lane on a one-way residential street. The result may not be slower traffic but it is less traffic since the street provides a less tantalizing shortcut to motorists who now can't pass each other.

It's become a more tantalizing shortcut for cyclists because the pavement is so smooth now.

[genec]

Parked cars seem to do a far better job. The problem with strips alone is that the visual clues of a wider street remain.

[LittleBigMan]

The only thing I've noticed to slow motorists' speeds is coming up on a wall of other motorists at a dead standstill.

[kf5nd]

having cyclists in the bike lane will calm traffic.

empty bike lane? nah.

[Helmet Head]

having cyclists in the bike lane will calm traffic. I sure have never noticed that.

I have noticed cyclists in a WOL (without a demarcated bike lane) calming traffic. But cyclists in a bike lane or shoulder seem to have very little if any effect on faster traffic in terms of lateral adjustment or speed.

[Helmet Head]

http://www.humantransport.org/bicycledriving/library/carystripes/carystripes.htm



Bike Lane Stripes:
Do they create better conditions for cycling?

...
It has been claimed by some striping proponents that adding lane-narrowing striping to existing unstriped roads may reduce motor traffic speeds by reducing the perceived width of the roadway. Compelling evidence exists that contradicts to this claim. In 1999 the Institute of Transportation Engineers published "Traffic Calming: State of the Practice", (FHWA-RD-99-135) a report on experiences with traffic calming in the US & Canada. From the section titled "Centerline and Edgeline Striping" (http://www.ite.org/traffic/tcsop/Chapter5c.pdf):

"Painting an edgeline several feet from the pavement edge has the effect of visually narrowing the roadway....In theory, the perceived narrowing could cause a modest speed reduction, just as a real narrowing causes a modest speed reduction. The theory is not borne out by empirical studies. Results from Howard County, MD, Beaverton, OR, and San Antonio, TX, suggest that vehicle operating speeds are as likely to increase as decrease with striping. One explanation is that centerlines and edgelines define the vehicle travel path more clearly, creating a gun barrel effect.

Results from the aforementioned studies could be dismissed because even with the narrowings, pavement and lane widths remained substantial. Yet, results from Orlando,
FL, where travel lanes were taken down to 9 feet, showed speeds to be unaffected (see figure 5.47).27 This psychoperceptioncontrol was not "tricking" anyone and hence was removed from both the centerline and edgelines."
Although many have tried, no scientific study has ever shown that segregation striping on ordinary streets improves safety for cyclists as compared to the same pavement space without the striping.

[Keith99]

I don't have any numbers, but recently they added a bike lane by removing a traffic lane on a one-way residential street. The result may not be slower traffic but it is less traffic since the street provides a less tantalizing shortcut to motorists who now can't pass each other.

It's become a more tantalizing shortcut for cyclists because the pavement is so smooth now.

There is one near me. Technically I would have to say it works, but calming is not the term I would use, perhaps slowing. Putting in a bike lane changed it from two lanes each way to one each way. I did not see any substantial decrease in traffic (though there might be during rush hour a time I never am on it). But calming no, get a slow driver and there is no way to pass. Road rage creating is more like it.

Oh and the section in question is so steep few cycle it, goint 3 sides of a rectangle to avoid it on bikes. But of course drivers think of it as something to benefit cyclists.

[Roody]

Usually bike lanes are designed to facilitate or expedite traffic, not slow it. I think new designs would be needed to actually slow motor traffic.


Meanwhile, I think cyclists in the traffic lane will slow motor traffic more than bike lanes will.