Consultants leading a cross-town traffic study plan to recommend roundabouts and changes to South Airport and Keystone roads, with a long-debated Hartman-Hammond bypass falling low on their priority list.

OHM Advisors is spearheading the East-West Corridor Transportation Study, a project funded by the Grand Traverse County Road Commission. The study area extends from Grandview Parkway south to Beitner Road and from US-31 east to Four Mile Road, specifically evaluating opportunities to improve east-west traffic on corridors under Road Commission control. OHM Advisors unveiled several proposed design scenarios – or “practical solutions” – to 200-plus attendees at a February public open house, and collected nearly 600 survey responses on those ideas.

That data was combined with economic, environmental, land use, safety, road operations, and equitable access analyses to rank the solutions, which range from installing roundabouts at key intersections and widening corridors to building a bypass or extending Cass Road from its new bridge across to US-31. The firm’s recommendations will be officially unveiled at an April 30 public meeting at the Hagerty Center from 6pm to 8pm, but OHM Advisors provided an advance preview of the results to project partners Tuesday.

According to the consultants, the most pressing opportunity for impact is redesigning South Airport Road. OHM Advisors is recommending using a “boulevard” configuration on South Airport between Garfield Avenue and Logan’s Landing, with a narrow median dividing traffic flow in either direction. Vehicles would be restricted from making left turns out of businesses – a major conflict point on South Airport today, particularly between Garfield and Barlow – and instead would turn right and then U-turn, or else make turns at intersections.

Rather than roundabouts throughout South Airport Road – one previously considered scenario – OHM Advisors is combining the boulevard design with proposed roundabouts at only a handful of key intersections, such as Garfield, Barlow, and Park (pictured). Lead Traffic Engineer Steve Dearing said that without a willingness to consider roundabouts, the Road Commission had few options to improve the safety of “mature” intersections like South Airport and Garfield. That intersection, one of the county’s deadliest, already has left-hand turn phasing and other features designed to facilitate traffic flow, but still results in drivers running red lights and vehicles “getting t-boned,” Dearing said.

“The safety improvements (at these intersections), you’re just going to be nibbling at them. You’re not going to make any real substantial changes unless you’re wiling to really go and do something like a roundabout,” Dearing said. “The fact is, roundabouts at these kinds of locations have been proven…you can see crashes reduced from anywhere from 40 to 70 percent, and the severe crashes that would cause someone to die or be seriously injured, those generally go down by 80 to 90 percent.”

A boulevard configuration with a handful of roundabouts would keep traffic moving throughout the corridor and significantly decrease travel and congestion time, according to consultants. The improvements are also less costly than other options. Another high-priority recommendation from OHM Advisors is widening Keystone Road to four lanes between Hammond and Cass roads, with a fifth turn lane available in areas like the Keystone Soccer Complex. The construction cost for widening Keystone – a project that could also include installing roundabouts at some intersections – combined with the proposed South Airport improvements would total approximately $6 million, consultants estimated. They compared that figure to an estimated $44 million in construction costs for a new Hammond Road bridge or bypass over the Boardman River (estimates do not include right-of-way acquisitions or other project expenses).

“We’re looking at cost versus value: where you can best invest your dollars for safety and operational improvements,” says Project Manager Matt Wendling. “If the Road Commission wanted to invest in creating another crossing, that would cost $44 million. Think about the amount of other improvements you could make with that money. You can also segment your investment, so instead of taking on the entire corridor of South Airport Road, we can look at that section between Logan’s Landing and Garfield and the dollar amount needed for that one segment.”

A Hammond bypass, or the possible extension of Cass Road to US-31, ranked low on OHM’s list not only for cost reasons, but because of environmental impacts, property acquisition challenges, and relatively minimal impacts on safety and travel times compared to other solutions. Wendling told meeting attendees Tuesday that the firm wasn’t “necessarily” ruling out a bypass, but called it a “long, long-term approach” that should take a back seat to more cost-effective, near-term solutions. OHM’s final report, which will be delivered to the Road Commission in May following the next public open house, will highlight immediate steps the organization can take, like signal optimization and creating an access management plan to reduce driveways along South Airport Road. Making the larger proposed improvements to South Airport and Keystone roads could take 5-10 years, Wendling said, with something like a bypass reserved for the distant future.

“There’s quite a difference in cost there between some of these improvements that you may be able to make and have a really great impact, versus adding another bridge,” said Wendling. “We just wanted to demonstrate how many improvements you may be able to make if you consider some of these smaller segments, as opposed to putting any available funding you have into one bucket."