Going on a Road Diet

I read your article "Sequoyah Hills Residents Seek Lower Speed Limit" with interest. [Citybeat by Chris Barrett, June 18, 2009] The particular stretch of Kingston Pike that was mentioned appears to have particularly narrow lanes, and I am not sure why its speed limit is 45, and I don't see how people can be driving 50-plus through that area.

One possibility for reducing the speeds and enhancing safety through that neighborhood would be to perform what's commonly called a "road diet" on that stretch, i.e. turn the four-lane road into a three-lane road with one lane in each direction and a center turn lane. Bike lanes can then flank the through lanes, which would encourage non-motorized travel to and from UT, the churches, and the shopping district west of there.

Furthermore, with such a conversion, traffic is inherently slowed, since the controlling speed would be set by the slower drivers. Turning traffic would no longer block the through lanes.

Finally, such a conversion would tie in nicely with the Cumberland strip's planned road diet as part of the planned changes to it. Previous studies have generally shown that four- to three-lane road diets do not reduce the actual road capacity to any significant amount; however, Kingston Pike is admittedly a very heavily traveled roadway, and it would be interesting to find out (say through traffic modeling) what effect such a conversion would have.

Nelson Chen