Category Archives: Transportation

Old planning “rules of thumb”: they ain’t necessarily so…

The Thriving Communities’ blog page, now being without our former outstanding “Blogger in Chief,” Tim Johnson, will be frequently sharing links to articles we think are valuable and interesting but often accompanied by less of our own commentary and critique than Tim offered in past months. Today’s share focuses on some old transportation planning “rules of thumb” and points out the need for some major changes of thinking in that realm. We think many of you who are interested generally in thriving, inclusive communities and how we should plan for them will be interested in this article: “Our old planning rules of thumb are ‘all thumbs’”  by Joe Cortright.

Following are some excerpts from the article:

“Old rule of thumb #3: We should require “enough” off-street parking for every use

“As Donald Shoup has shown, parking requirements spelled out in zoning codes—often based on formidably inaccurate estimates … lead to a situation where every business’s parking lot is sized for the peak hour of the peak day of the year (holiday shopping season at the Mall, example). Not only does this produce more parking than is needed the rest of the year, it turns out that parking “requirements” grossly overstate demand even in peak periods, and especially for urban uses where more people arrive by other means, and park for shorter periods of time. The product of this rule of thumb is that parking

The wider the lanes, the easier it is to speed. Credit: Pier-Luc Bergeron, Flickr.
The wider the lanes, the easier it is to speed. Credit: Pier-Luc Bergeron, Flickr.

is over-supplied, destinations are further apart than they would otherwise be, and walking, transit and cycling are non –functional.”

“New rule of thumb #1: Closer is better”

“Having more different destinations close at hand facilitates a wide range of mode choices, especially walking and cycling. Mixing uses, which is often anathema under traditional zoning codes turns out to be desirable for consumers and expeditious for transportation.”