A consulting group tasked with analyzing potential routes for a long-discussed bypass over the Boardman River has identified a Hartman-Hammond crossing as the “best build” scenario, telling the Grand Traverse County Road Commission (GTCRC) Thursday that alternative routes using Cass Road or the former Sabin Dam site faced significant issues and were less desirable than Hartman-Hammond. The consultants are expected to hold a public meeting in early March to talk through the group’s findings before delivering a final report to the Road Commission by the end of March.

GTCRC hired OHM Advisors to guide the organization through a planning and environmental linkages (PEL) study, a federally mandated process when making transportation decisions like building new highways and bridges. The PEL aims to identify a new possible crossing over the Boardman River and analyze the impacts of the route, ranging from cost of construction to land acquisition requirements to environmental, social, and economic effects.

Last fall, OHM Advisors identified three possible routes to connect Keystone Road to US-31 over the Boardman River. The first and most expensive option – at an estimated $81.4 million – would require construction of a new causeway bridge over the Boardman River valley to connect Hammond and Hartman roads. A second option called the Sabin Dam crossing, estimated at $59.2 million, would start at Birmley Road and cross Cass and Dracka roads, snaking up to Silver Pines Road at US-31. That route would still require a bridge, though it would likely be one-fourth the size of a Hartman-Hammond bridge. A third option, estimated at $53.8 million, would utilize existing infrastructure at the recently rebuilt Cass Road bridge by crossing from Keystone over Cass, Broad, and Dracka roads up to Silver Pines Road. In that scenario, GTCRC could potentially take the existing Cass Road bridge and widen it to accommodate more lanes, or else build a parallel structure so the route can expand from two lanes to four or five.

At Thursday’s GTCRC meeting, Bill Zipp of OHM Advisors said the firm has “moved into the final phase of the study and is ready to move towards what we are calling a locally preferred alternative.” That recommended route is the Hartman-Hammond crossing, which the consulting group said would be the most effective at alleviating crosstown traffic congestion, reducing traffic by 37 percent on South Airport Road by 2045 compared to a no-build scenario. A Hartman-Hammond crossing would also cause the least number of residential displacements, offer the “most logical east-west connections with existing roads on either side of the river,” and provide the “most suitable and direct route” for a bypass over the Boardman, according to OHM.

With environmental opposition sinking a proposed Hartman-Hammond bypass in the past, Zipp noted Thursday that the estimated 2,200-foot bridge could be designed in such a way as to “minimize the impact to the wetland” underneath by putting the structure 75 feet in the air and using minimal pier pilings in the floodplain. “It’s not going to be cheap, but it minimizes (the impact) to the ground below,” he said.

Zipp also said the Hartman-Hammond route was the least environmentally impactful of the three routes. The Sabin Dam crossing would fragment the Boardman River Nature Center and Grand Traverse Natural Education Reserve and disrupt a planned pedestrian bridge completing a loop around the property. The Cass Road crossing would not only put “noise and other highway-related concerns into the heart of the reserve” but impact the Robbins Farm conservation easement property and the historic Meyer property, home to the Great Lakes Incubator Farm, according to OHM. That route would also require tunneling under the existing railroad west of Cass Road, “impacting wetlands and the groundwater feeding the wetlands and adjacent streams,” the group determined. Though less expensive to construct, the Sabin Dam and Cass Road crossings would require more residential displacements and be less effective at alleviating South Airport Road traffic than Hartman-Hammond, according to OHM. “There’s a lot of real problems with these two alternatives,” Zipp told GTCRC board members.

According to Zipp, the Grand Traverse Conservation District has issued a letter stating its opposition to the Sabin Dam and Cass Road routes. OHM is planning to appear before Grand Traverse County Parks and Recreation commissioners in February, where Zipp said he anticipates that board will also pass a resolution objecting to those two crossings. That could mean the only scenarios recommended for further study when OHM delivers its report would be the Hartman-Hammond crossing and a no-build scenario. The firm indicated, however, that a no-build scenario would be “less desirable” than Hartman-Hammond, saying that opting to do nothing “does not provide for the continued growth of the Grand Traverse region,” offers “no relief or accommodation for existing and future network congestion concerns,” has “no benefits or improvements to non-motorized connectivity,” and “does not improve area road network resiliency or redundancy.”

Even if GTCRC were to eventually pursue a Hartman-Hammond crossing, Zipp acknowledged that – in addition to its hefty price tag – there are still numerous outstanding issues to address with that option, including the exact route path. “The connection to US-31 is yet undefined,” he said, noting that because of the highway’s grading, there are “engineering challenges” all along the corridor. The crossing could connect out to McRae Hill Road or end at a juncture with a relocated Silver Pines Road as two options, Zipp said. “These can be vetted out in the NEPA process,” he added, referring to the National Environmental Policy Act. NEPA dictates requirements for the next phase of transportation planning, in which an option like a Hartman-Hammond bridge crossing would be analyzed in significantly more detail.

According to an OHM timeline, the consultants will hold a public meeting in early March (March 3 is listed as a target date) to talk through the group’s findings before submitting a final report to GTCRC by March 25, closing out the PEL process – or this particular phase of the bypass planning study – by the end of that month.