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VTBIKEPEDPOLICY-L:

I recently received a message about some design changes the Burlington
Bike Council is considering for Mansfield Avenue, a relatively wide,
gently sloping street near the University of Vermont, with a school and
institutions fronting on one side, and a wide nature strip and homes on
the other side.  Mansfield Ave. is at the perimeter of Burlington's
street grid.

As usual, I had an adverse reaction to the plan that's in play.  Here's
a snip from my reply to the proposal being considered... some things to
remember when thinking about street space allocation:

>
> Here are some bicycle engineering fundamentals to keep in mind when allocating street space:
>
> Bikes ARE traffic:
> It's often forgotten, but this is the single most important principle.  Bicycles are vehicles and are treated as such by the motor vehicle codes.  When designing a street, think of a cyclist as a vehicle that has a few special properties.  Better yet, think of cars and trucks as vehicles with a few noxious properties.  Bike lanes reinforce a segregationist, "bikes are toys" world view.
>
> Grade:
> Grade is an important factor in a biker's minimum speed and required width.  It is also a key factor in speed differential.  In general, when traveling downhill, cyclists should, and do, join the flow of motor vehicles, reducing speed differential and natural passing opportunities.  It is preferrable that cyclists take the lane when descending, where the roadway is high access, and in Vermont, where shoulder/gutters surface is poor.  Like other low-power-to-weight vehicles, bicycles could use a climbing lane.
>
> Bikes have width:
> Sure there's the actual width of the bike, which is not 2 inches of tire width, but the 4 feet required by trailers and panniers.  Then there is wobble space, which can be a few inches on either side when travelling at speed -- on descent if the road has smooth surface and mellow curves. But it is a few feet when ascending slowly on bad pavements.  And there is also shy distance, which is greater at speed.   At any time, bikes have a width of at least a few feet.
>
> Gutters have width:
> Burlington has to start recognizing that there is such a thing as a gutter.  Because of the amount of crap that accumulates on the streets, and the prominence of drains, gutters in Burlington are about three feet wide.
>
> Gutters are not bike lanes:
> Bikes are very sensitivy to surface.  Gutters are not designed for travel. Indeed, they are often marked with a fog line.  Bikes shouldn't be in the gutter for the same reasons that cars should not.
>
> Doors have width:
> Car doors have width and are a high hazard for cyclists.  Obviously, if the current configuration is maintained, don't be tempted to stripe the door zone as bike lane.
>

One more point that I should add is that pavement is actually occupied
for only a very small fraction of the time.  That's one reason traffic
calming works so well.  Allowing alternative uses to overlap is space
efficient.

-Peter
--
----------------------------------------------------------
Peter Duval                               (sent from emba)
98 Sleepy Hollow Road                      +1 802 899 1132
Essex Jct., VT                                fax 899 2430
USA 05452-2798                  http://www.uvm.edu/~pduval

--
----------------------------------------------------------
Peter Duval                               (sent from emba)
98 Sleepy Hollow Road                      +1 802 899 1132
Essex Jct., VT                                fax 899 2430
USA 05452-2798                  http://www.uvm.edu/~pduval

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