MDOT plans ‘dynamic shoulders’ as part of $76 million U.S. 23 overhaul

Thinking Highways
By Thinking Highways February 25, 2015 10:57

MDOT plans ‘dynamic shoulders’ as part of $76 million U.S. 23 overhaul


The Michigan Department of Transportation (MDOT) is seeking public comment on a plan developed to help relieve rush hour traffic on U.S. 23 north of Ann Arbor.

The $76 million project will include the implementation of an active traffic management system that will use “dynamic shoulders” to open additional lanes of traffic. The plan also calls for the replacement of four bridges that do not meet state standards and general maintenance on more than 10 miles of highway from the U.S. 23 and M-14 interchange to Silver Lake Road north of Whitmore Lake.

The biggest change for motorists will be the traffic management system that will open the interior shoulders of the road to help relieve rush-hour traffic. During peak morning hours, the left shoulder of southbound U.S. 23 will be opened to vehicles and light trucks. The left shoulder will be open on the northbound side of the highway during evening rush hours.

Signals will be installed over the roadway to indicate when the shoulders are open or closed.

An environmental assessment prepared by MDOT said the goal of the system “is to develop safe, efficient, and sustainable transportation improvements to assure that the corridor will meet the current and future highway operations with the use of state of the art traffic control measures along with improved infrastructure.”

The assessment showed that The Average Daily Traffic (ADT) on U.S. 23 between the west U.S. 23/M-14 interchange and Silver Lake Road interchange ranges from about 60,000 to 65,000 vehicles per day. Morning and evening congestion is heightened during summer months due to recreational travel and during winter months due to poor road conditions.

During the three-year period of 2009, 2010 and 2013 — the intervening two years were discounted due to construction taking place — there were 845 crashes on the corridor, 33 percent of which occurred during icy or wet conditions. There were two fatalities and 13 severe injuries during the three-year period.

“The predominant crash pattern along the U.S. 23 corridor was rear-end crashes due to slowing or stopped traffic during the a.m. peak for SB U.S. 23 and during the p.m. peak for NB US-23,” the assessment stated.

The dynamic shoulders could help alleviate congestion caused by these crashes by allowing traffic to flow more smoothly along the heavily travelled corridor. MDOT spokeswoman Kari Arend said the display signs determining whether the shoulders are open or closed to traffic will be controlled by Statewide Transportation Operating Center in Lansing. She added that the Freeway Courtesy Patrol, a unit within MDOT that provides assistance to stranded and distressed drivers, will also be making sure that the shoulder is ready to be opened during peak hours.

MDOT will be hosting a public hearing on the plan Thursday, Feb. 26, that will include a presentation of the environmental assessment and an opportunity for the public to give feedback. Approximately 230 area residents and officials attended two prior meetings held in December 2013 and August 2014.

The upgrades to the shoulders to allow for increased traffic load and the installation of the traffic management system are expected to cost approximately $29.5 million. MDOT expects to spend an additional $14 million on intelligent transportation systems.

“The ITS will include installation of additional traffic camera locations and electronic message boards to better inform the public of travel conditions by identifying travel times to interchanges, construction dates and times, and traffic incident notification,” according to the assessment.

Bridge replacements at Six Mile, Eight Mile and North Territorial roads will also cost approximately $14 million and are scheduled to take place during the 2017 construction season.

According to a “green sheet” in the environmental assessment, both lanes of the highway will be maintained in each direction during peak hours, and traffic will be restricted to one lane during night and off-peak hours. Traffic on U.S. 23 ramps may be closed for short periods during reconstruction, and traffic on local roads will be detoured while bridges are being reconstructed.

Traffic will be maintained on at least one local road bridge while the other two are being replaced.

The bridge carrying U.S. 23 over the railroad in Northfield Township will also be replaced at a cost of $4.6 million. On-ramp extensions at North Territorial, Eight Mile, and Six Mile roads as well as M-36 will cost about $6.3 million to complete, and the general capital preventive maintenance jobs on the whole stretch of highway will total about $6.4 million. Approximately $600,000 has also been set aside for repairs to the Warren Road and Joy Road bridges over U.S. 23 just north of Ann Arbor.

Arend said the project will be put out for bids in August 2016, and MDOT officials anticipate that work will begin on the project before winter sets in. The bulk of construction is expected to be completed during the following construction season and the project’s target completion is August 2017.

Simply expanding the highway to three lanes in each direction at all times was deemed too costly early on in the process, but MDOT did consider a number of alternatives to the traffic management plan, including making the shoulders high occupancy vehicle (HOV) lanes for vehicles with more than one occupant.

According to the environmental assessment, there were too many issues with enforcement and safety to make the HOV plan viable. There is no current Michigan statute governing HOV lanes and there would be a multitude of difficulties for law enforcement, including attempting to recognize violating vehicles

Story: MLive.com

Thinking Highways
By Thinking Highways February 25, 2015 10:57