Minnesota Standards Should Change from 12 Foot Lane Widths to 11 Foot Lane Widths

I attended a luncheon about "Great Streets" at the Sensible Land Use Coalition yesterday.  The conversation was about MnDOT, Hennepin County, and HR Green's (a consultant working with local cities) experience of bringing the Complete Streets concept to Minnesota.  The main idea is to make our transportation system work for all modes of transportation (transit/bicycles/pedestrians in addition to vehicles).

Julie Skallman from MnDOT explained the excruciatingly slow process MNDOT is undertaking to implement Complete Streets concepts.  To me, the no-brainer decision is to use 11 foot wide lanes instead of 12 foot wide lanes. However this is in conflict with the Minnesota design rules which state "wherever possible, lane widths of 12 feet, rather than 11 feet, should be used."  

Narrowing roads results in shorter crossing distances and reduced traffic speeds.  This improves the environment for pedestrians and bicyclists. 

The research also points to 11 foot lanes being as safe as 12 foot lanes (according to NCHRP Project 17-26).  A big reason is that motorists drive more cautiously in narrower lanes.  Narrower lanes would have reduced the numerous speeding complaints I received from residents during my tenure in Maple Grove.

A quick check of MnDOT's website shows there are 290,588 lane miles in Minnesota.  Assuming we trimmed one foot off each lane, that would equate to 35,222 acres (55 square miles) of less pavement (assuming all of the roads are paved).  To put that in perspective, the city of Minneapolis is 58.4 square miles including the lakes and rivers. 

Imagine the economic and environmental benefits of shifting the standard by one foot.  Why would this decision take 2+ years of study?  The rules should be re-written to make 10 foot lanes allowable in urban settings, 11 foot lanes the standard across the state, and 12 foot lanes allowed if justified through a variance process.

Comments

[Reuben]

I agree, although my experience has been that communities are routinely citing "right-of-way constraints" or "cost constraints" and building 11-foot lanes anyway everywhere except for interstates.

I also think we need to reconsider how we handle our "clear zones" that effectively expand our 11' lanes into 13'-15' lanes.

[Froggie]

I don't think a blanket 11ft standard should happen. The type of road should be taken into account as well. Freeways and Interstates should remain 12ft. Major truck routes, both urban and especially rural, should remain 12ft as well. In urban areas, I can agree with going with a narrower standard, though one should take into account here how bicycle use plays in. Correct me if I'm wrong, but a 13ft curb lane is preferred for an on-street bike route without dedicated bike lanes.

[Froggie]

Also, since you mention it, less than half of that lane mileage (about 122K total) is paved, with all but about 6,600 of that being asphalt. The rest is gravel, dirt, or just-under-12K of "unknown".

http://www.dot.state.mn.us/roadway/data/reports/2010/mileage_lanemiles/fzstmcsf.pdf

[Eric]

I also think we need to reconsider how we handle our "clear zones" that effectively expand our 11' lanes into 13'-15' lanes.
Source: http://www.hrbponline.com/