“Would Sharrows work in Detroit?”

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

Section 9C.07 Shared Lane Marking
01 The Shared Lane Marking shown in Figure 9C-9 may be used to:
A. Assist bicyclists with lateral positioning in a shared lane with on-street parallel parking in order to reduce the chance of a bicyclist’s impacting the open door of a parked vehicle,
B. Assist bicyclists with lateral positioning in lanes that are too narrow for a motor vehicle and a bicycle to travel side by side within the same traffic lane,
C. Alert road users of the lateral location bicyclists are likely to occupy within the traveled way,
D. Encourage safe passing of bicyclists by motorists, and
E. Reduce the incidence of wrong-way bicycling.
02 The Shared Lane Marking should not be placed on roadways that have a speed limit above 35 mph.
03 Shared Lane Markings shall not be used on shoulders or in designated bicycle lanes.
04 If used in a shared lane with on-street parallel parking, Shared Lane Markings should be placed so that the centers of the markings are at least 11 feet from the face of the curb, or from the edge of the pavement where there is no curb.
05 If used on a street without on-street parking that has an outside travel lane that is less than 14 feet wide, the centers of the Shared Lane Markings should be at least 4 feet from the face of the curb, or from the edge of the pavement where there is no curb.
06 If used, the Shared Lane Marking should be placed immediately after an intersection and spaced at intervals not greater than 250 feet thereafter.
07 Section 9B.06 describes a Bicycles May Use Full Lane sign that may be used in addition

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

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2 Responses to ““Would Sharrows work in Detroit?””

  1. Streetsblog.net » Houston METRO Expands Access By Removing Seats Says:

    […] something away, you’ve improved options for three types of riders.   Also on the Network: m-bike wonders if sharrows are the right prescription for Detroit; Publicola criticizes the Seattle Times' […]

  2. Milford DDA recommends sharrows | m-bike.org Says:

    […] Sharrows are a great, low-cost solution in many cases, especially where there is no parking and widening a road for bike lanes is too expensive. Bike lanes and/or sharrows are a much better, safer alternative to the side paths that had been proposed earlier this year in Milford. […]

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