Schubley@... wrote:

> Wayne,
>
> A comment, responding only to the other comments on "doubling up." (My
> computer is choking on the web page this afternoon, and I was only able to
read
> pieces of your paper.)
>
> First of all, I hope this isn't an argument of ideologies. Either people
> double up or they don't. Either it's been observed or it hasn't. Let us
always
> praise the objective gathering of data.
>
> I've been a fan of wide outside lanes ever since 1978, when I read Greg
> Jones's paper about their success in Baltimore County. Simple, cheap,
effective,
> non-pork-barrel.
>
> It was around 1990 that Gihon Jordan of the Philadelphia City Streets
> department told me about some aspects of the design of Walnut Street (one way
> westbound) in the vicinity of its bridge crossing over the Schuylkill River.
Gihon
> had observed doubling up in a lane he reported at 16 feet wide.
>
> I have dutifully reported this observation on various e-mail forums over the
> years. Each time, respondents, typically from newer sunbelt cities, have
> replied, "Nah, they wouldn't double up in a lane that narrow."
>
> Once when I saw Gihon, I relayed those replies to him. His response: "They
> do it in Philadelphia." He and I had a good laugh over the fact that
> Philadelphians, who are accustomed to old narrow streets, are willing to drive
in a
> narrower space than, say, residents of Harrumpf, Nevada.
>
> 16 feet does sound extreme -- that's eight feet per car. If your car is six
> feet wide, as most cars are, that leaves only one foot of shy distance on
> either side. But then again, you'd be going quite slowly.

IF the useable pavement width is in fact 16 ft on Gihon's Walnut St, then that
is an
unusual one-off type situation that would benefit from a sign such as Form
Single Lane as
you suggest below.

>
>
> Again, Gihon said he'd observed doubling up, and I have no reason to doubt
> him.
>
> The city of Allentown has a wider example. Jefferson Street, which I
> estimate has a southbound lane at least 24 feet wide, has had routine doubling
up for
> decades. It was on my route to work for over a year (1979-1980), and when I
> drove, I participated in the doubling up. When I rode my bike, I had no
> problems on that stretch. I don't recall how overtaking motorists responded
to me;
> I only recall that it was a non-event as far as I was concerned. Recently,
> the city has added a "form single lane" sign in an apparent effort to avoid
> doubling up.
>
> In conclusion:
>
> _If_ doubling up becomes a problem, why not use the sign that Allentown uses?
> I don't know why they put it there (I doubt their reasoning has anything to
> do with bicycles) but it gets you the beahvior you want, cheaply and simply.
>
> Wayne has a good point that extra-wide outside lanes are vastly preferable on
> fast descents. Wayne, do you have a maximum number? Say, 16 feet (probably
> okay everywhere but Philadelphia) increaasing to 17 when the road goes around
> a curve?
>
>

I don't suggest extra extra width on fast descents. I actually espouse the
opposite. When
bicyclists are at high speed, there is less "need" for motorists to overtake,
hence less
need for additional width. When I descend, I position myself in the center of
the lane no
matter what the width because I want to communicate to motorists to not pass
using my
lane. They should move into the adjacent lane if it exists or wait until the
descent is
over.

As I note in my paper, in my experience when the lane is wider than 15 ft,
debris
typically accumulates on pavement unless there is significant high speed truck
traffic to
help push it further right. In that case 16 ft can be useful for the extra
clearance from
the heavy truck traffic.

I think each road segment should be evaluated individually to access the
possibility of
doubling up and debris accumulation. 17 ft may be OK in places (we've got 18 ft
on a
short low speed road segment here that works OK), but the reality is that lanes
that wide
will probably raise red flags by the engineers designing it, so I'm most
comfortable
espousing 16 ft at most.

Wayne