08-12-2021, 12:41 PM
(This post was last modified: 08-12-2021, 12:45 PM by danbrotherston.)
(08-12-2021, 09:43 AM)jamincan Wrote: Personally, I think roll curbs are acceptable where there is no on-street parking. I personally might actually prefer them to a full curb lane in that case, as I'm not convinced the full curb provides any better protection than a roll curb and think it's main benefit is that it acts as a deterrent to people using the lane for parking.
I'd happily reconsider my opinion if studies have been done on the difference between them and how they function in different contexts, but the science is pretty scant and what research is out there is limited by the huge number of confounding variables.
So, in terms of parking, I don't think "no parking" is the question, I think "no parking demand" is the question, which is very different. In fact, you will find MORE cars parking when there is a bike lane, then when there is not. For example, specific to the Ottawa bike lanes, I do frequently see vehicles stopping in the bike lanes for delivery (and taxi) to the few homes on the street, I suspect those drivers would have parked in the empty driveways before. And yeah, some of our roads have little demand for parking, like much of F-H has absolutely no frontage, but I still come across vehicles in the bike lane from time to time, although it is rare. The point is, if it is possible for drivers to park, they will. (See also Queen St., which never had a parking problem, but now does).
But roll curbs are more problematic than just parking. I mean, for one, the current roll curbs are INCREDIBLY permissive, like orders of magnitude more permissing than the curb cuts installed to actually access bike infra, and this is just insane.....how is that allowed, I don't understand. But the effect is that drivers will choose to drive in the lane sometimes, for example to go around a turning vehicle. This is what the lanes are supposed to avoid. But roll curbs are not an effective deterrent, drivers will still choose to drive in the lane sometimes.
The only other question is accidental intrusion, which, I dunno, I'm not a physics major, possibly barrier curbs are not more effective, but certainly barrier curbs would be more effective at regaining a drivers attention if they do accidentally deviate from the lane...again, the roll curbs are so permissive that a drunk, or distracted, or passed out driver could easily not notice crossing the roll curb. A barrier curb, if it is at all possible for them to be aroused, they absolutely will be, and if that means they need a new front tire or rim on their car, well, I'd rather that than my child needing a new father.