Ann Arbor’s new “FlexRoute” dynamic shoulder lanes

Flexroute lane is to the left of the vehicles – left of the yellow line.

The Michigan Department of Transportation (MDOT) recently opened flexroute lanes along a nine mile segment of US 23 north of Ann Arbor. This was done as a cost saving alternative ($92 million) to three-laning the freeway ($400 million) through this very busy corridor. Here’s a link to a digital brochure on the project.

Sources: MDOT and MLive

The flexroute lanes operate in both directions during peak rush hours and special events, such as University of Michigan football games; and when regular travel lanes are blocked by accidents or construction. Unlike some flex lanes, these lanes are improved inside shoulders (a.k.a. dynamic shoulder lanes) that are situated on opposite sides of the freeway’s grass median, so they are not reversable lanes.

Source: MDOT

Overhead signals spaced along the route notify motorists if the flexroute lanes are open or not. The system opened the week of November 13th and operates between Exit 54 (M-36) on the north and Exit 45 (M-14) on the south.

I was pleased to see on Thanksgiving Day that no drivers were disobeying the closed flexroute lanes signal. My son, who commutes this route regularly, reports that he has yet to see anyone using the flexroure lane when it is closed. Given the propensity of Michigan drivers to flout speed limits, it is reassuring to see these rules being followed.

A flexroute such as this appears to be an excellent active traffic management option for reducing peak hour congestion without going to the expense of widening an entire highway. Whether a flexroute creates the same kind of  induced demand that standard road/highway widening does will be interesting to learn.

While dynamic shoulder lanes are an impressive and transferable idea to other places here in Michigan and elsewhere, this planner would still like to see alternatives attempted that actually reduce the number of cars on the road, especially those with a single occupant. For this particular corridor, the previously discussed commuter rail option along the existing tracks connecting Ann Arbor and Howell (located just west of Brighton) would be a good option to consider. HOV (high occupancy vehicle) or BRT (bus rapid transit) lanes on US 23 would be more difficult to implement without adding a third lane the entire length of the corridor between the two cities. Regardless, MDOT should be commended for trying out an alternative solution to the congestion problems that can plague US 23 north of Ann Arbor.

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7 Responses to Ann Arbor’s new “FlexRoute” dynamic shoulder lanes

  1. As I have driven this route this fall, including one run on the shoulder lane during an evening rush hour, one question has come repeatedly to mind: Has anyone worked out how the MDOT snowplow guys are going to handle snow removal along this dynamic shoulder lane? At some points the shoulder lanes are so close together that the usual snow plow process would simply throw snow across the median into oncoming traffic. In nearly all instances along this route, there is insufficient land area in the reduced median to accommodate plowed snow piles from both sides.

    The alternatives are not great: (1) to scoop and haul from this lane, or (2) to plow from left to right across all three lanes to deposit all of the plowed snow along the right-hand sides of the freeway.

    I hope that the MDOT cyber overlords watching this route have considered this issue and have a plan in operation already, but my cynical and jaded bet is that they haven’t thought that all the way through.

    Liked by 1 person

  2. Scott Barb says:

    Our county planning staff just had a planners luncheon on this very topic. Our MDOT representative for the University Region put together a great presentation and was able to illustrate the flex route system and answer many questions. I’m not sure how snow removal will be handled, but i know the left lane will only be open during times of peak demand or during accidents, slow downs, etc. I can will contact her and find out since i’m interested in your question as well…

    Liked by 1 person

  3. krieg45 says:

    Answer to snow clearing question: Washtenaw County Road Commission is contracted by MDOT to plow US 23 in its territory. After discussing various alternatives, they have decided to assign three plows to the task. These will run simultaneously, one in each lane with the inner lane’s plow in front, the middle lane second, and the outer lane third. This moves the snow to the right-hand shoulder. Presumably another plow is used to clear the shoulder later, perhaps because only three plows could be assigned to the task at any one time. [The three-plow plan was discussed at the Washtenaw Area Transportation Study (WATS) Policy Committee meeting in November.]

    This morning (Dec. 12) was their first opportunity to test the system with real snow! At a transportation-related meeting this morning, I heard one person say they had seen this in action from the opposite lane, and it was “impressive”. Another person, who commutes daily from Howell to Ann Arbor, said the roadway was clear all the way.

    Liked by 1 person

  4. krieg45 says:

    General observation: City of Ann Arbor transportation planners have complained all during the planning process that the FlexRoute will only push the congestion further south, onto Ann Arbor streets, which are all maxed-out on right-of-way. MDOT responded by lengthening a turning ramp north of the west triple-decker (I’m not clear which lane), to provide more space for backed-up traffic. My friend who commutes from Howell noted that traffic is indeed usually backed up on US 23 during morning peak, both at Ann Arbor’s Main Street, and Plymouth Road. Today (Tuesday Dec. 12) traffic trying to get to Main Street was backed up well north of the west triple-decker in stop-and-go mode. (He has observed that Tuesday is usually the most congested day during morning peak, and of course the snow on city streets slowed traffic significantly.)

    Three or four years ago, MDOT proposed that AAATA run buses from a new park-and-ride lot at US 23 into Ann Arbor. As a member of the AAATA Board of Directors (SPEAKING FOR MYSELF, NOT FOR THE AAATA BOARD) I have been concerned that unless some provision is made for buses to bypass the worst of the congestion, it would be a waste of resources used by very few people. Why get out of your car, wait for a bus, and pay to board, only to rejoin the same congested stream of traffic you were in 10-15 minutes earlier? The solutions employed elsewhere have each been rejected. HOV lanes, which would be a great benefit in many ways, have been nixed because Michigan State Police solemnly swear or affirm that they would be unable to enforce HOV lanes. I believe MSP also disallowed authorizing buses to run on the right-hand shoulder. The best solution, seen in places like Seattle, San Francisco, and Los Angeles, is to build special HOV or bus-only lanes, complete with over/underpasses. Seattle, of course, has a bus+light rail tunnel under the entire downtown. Brisbane, Australia, has a major investment in its system of “Busways”, including exclusive bridges and tunnels. Such spending is not politically acceptable in Michigan – or not yet! Michigan does own the parallel railway line, but does not care to invest enough in it to be useful for passenger service. Let’s hope that will change soon.

    – Larry Krieg


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