I was in a meeting a few weeks ago and heard the term “Road Diet” to describe reducing the auto capacity of a road. I found it quite curious (and a little humorous). Serendipitously I was reviewing the archive of webcasts for the PSU Transportation Seminar Series and came across a presentation specifically on the topic (video stream) by Jennifer Rosales, a traffic engineer in the local office of Parsons Brinckerhoff.
I was in a meeting a few weeks ago and heard the term “Road Diet” to describe reducing the auto capacity of a road. I found it quite curious (and a little humorous). Serendipitously I was reviewing the archive of webcasts for the PSU Transportation Seminar Series and came across a presentation specifically on the topic (video stream) by Jennifer Rosales, a traffic engineer in the local office of Parsons Brinckerhoff.

For those who don’t want to watch the whole presentation, the slides are available in PDF form (1.5M).

I also found this web-formatted image at Urban Cartography

The classic formula for a road diet is to take a four-lane road and reconfigure it as one lane in each direction, a center turn lane, and bike lanes in each direction. Jennifer’s research suggests that this treatment can be successful on streets with 20,000 average daily trips or less.

One of her case studies is 4th Plain Boulevard in Vancouver. In addition to improving mobility for bikes, she found that the street was perceived as safer and activity on the street increased. She was able to measure increased sales for businesses on the street during a period when the general district was experiencing a downturn in business.

Further, no diversion of traffic onto other streets was observed!

Have you got a street you’d like to put on a diet?