[SDCBC] Reasonable max speeds in a bike lane?

[Serge Issakov]

On 8/17/07, JonIsaacs at aol.com <JonIsaacs at aol.com> wrote:

>  Most cyclists fit nicely inside 44cm wide bars.  44cm is only about 17
> inches,  If you assume that the cyclist is 1.5 feet wide and are riding with
> their left shoulder near the line, that leaves 3.25feet  from the TIRE to
> the edge of the road.
>
>  Certainly that is plenty for someone who is carefully riding at 25mph or
> more, paying attention to what is ahead, etc.

I disagree.  At 25 mph, three feet (and it's really only 2 feet from
your right elbow) is not very much space to avoid a car that suddenly
pulls out of a driveway, for example, and riding that far right
shortens the sight lines to and from you.


>  I find it ironic that you would find having two feet to your right a
> concern when in the past you have stated that you are comfortable riding in
> a close pace line which means you are following someone more closely than 2
> feet.  At 25mph in a paceline 2 feet is about 1/20th of a second, well
> beyond the reaction time of even the fast human, so one is a sitting duck.

Totally different situation, for at least these reasons:

1) the paceline itself is much more conspicuous than a single solo
rider, so the risk of not being noticed is lower.
2) if you're moving at 25 mph relative to the ground, you're moving
much slower, practically 0 mph, relative to the other riders in the
paceline.  Even in a rotating pace line one line is typically moving
only 1 or 2 mph faster than the adjacent line.  At 2 mph 2 feet is
covered relative to each other in about 2 seconds.
3) the risk of riding near another rider moving at the same speed as
you is not the same as riding that close to a car that could pull into
you from the side.
4) I recognize that it's a risk, and it's one I'm willing to take.
5) I don't do pacelines in heavy traffic.

Having said that, in a place like La Costa Blvd going west from El
Camino Real to 101 where there are no places for traffic to turn in or
out of to the right, it's reasonable to ride near the edge at fairly
high speeds, paceline or not.

Serge