That question was recently posted on the Detroit Bikes email list.

Perhaps it’s best to first answer the question, “What are sharrows?”

Sharrows are standard pavements markings as shown on the right. They are used on roads that are designated bike routes where there is not enough pavement to include a bike lane. The sharrows provide guidance to the cyclists on where to ride on the road. Cyclists should ride through the center of the marking.

Of course these pavement markings also let drivers know about the presence of cyclists.

All signs and pavement marking designs and uses are defined by the Manual on Uniform Traffic Control Devices (MUTCD). We’ve listed the MUCTD information at the end.

Would Sharrows work in Detroit?

Yes, but only in limited instances, primarily when:

• There is not enough road width for bike lanes (even after a Road Diet)
• There is either no on-street parking or high-use on-street parking

Most city of Detroit roads do not meet the above checklist.

There is enough room for bike lanes on a majority of roads. For example, a recent non-motorized planning analysis found that over 90% of the roads in Detroit’s near east side would support bike lanes without any widening. The planner said 50% is considered excellent in other cities. He’s never seen a street network more readily available for bike lanes.

On Detroit roads without enough room for bike lanes, the parking is typically sporadic and not high-use. Why is this a big deal? On streets with parking, the sharrows would be located 11 feet from the curb. But, if there are rarely any parked cars on a road, does it make sense to ask cyclists to bike 11 feet from the curb irregardless? Probably not.

But there are some Detroit streets that could benefit from sharrows. For example, the curved entrance ramps from Jefferson and the Macarthur Bridge (to Belle Isle) could use sharrows to lead cyclists to and from the bike lanes.

Another good use of sharrows is to provide continuity to a bike lane when some sections of the road become too narrow. We’ve heard excuses that a road can’t have bike lanes because one short section is too narrow. Sharrows eliminate that excuse.

Of course the Detroit suburbs may also have more opportunity for sharrows since their roads are less overbuilt compared with Detroit’s.

Currently the cities of Flint and South Haven have sharrows with at least a couple others looking into them.

MUTCD Section on Sharrows

The League of Michigan Bicyclists also has more information on sharrows in their advocacy toolkit.

Tags: bike lanes, Detroit, MUTCD, sharrows

This entry was posted on Monday, August 16th, 2010 at 4:15 pm and is filed under Detroit, On-road bicycling. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.