A Look at the I-75 Truck Lanes Study Results

State DOT camera showing congestion on I-75 North at State Route 155 in McDonough.
(Georgia DOT photo)

Last fall, Henry County solicited a study to answer the question: ”Is state route 155 the appropriate end point for the I-75 Truck Lanes?” Many residents had raised concerns believing the truck lanes will only worsen traffic congestion. The results from the county’s study are now available.

I-75 Truck Only Lanes

First, some background about the project: Georgia DOT is planning to construct truck-only lanes on I-75 North. The project extends from I-475 in Macon to McDonough. There would be two barrier-separated travel lanes built parallel to the interstate. Presently, the state’s plan would end the truck lanes near Bethlehem Road. Then, they merge back into regular traffic. To accommodate the merge, an auxiliary lane would extend from Bethlehem Road to state route 155. Because of this, I-75 North would have four lanes between exits. In addition, the project would build another auxiliary lane between exits 216 and 218.

Georgia DOT held a public open house about the project in 2020. The open house remains available for residents to learn more. Right now, the project plans to start construction in late 2026. It would open to traffic by 2031.

Henry County Study

Many Henry County residents have raised concerns about the truck lanes ending at an already-congested location. They have frequently remarked the lanes should extend north to I-675. The county solicited proposals last fall to study this possibility. They hired Croy Engineering of Marietta to lead the study. Specifically, the study considered the following:

  • Address public concern regarding potential impacts of the CVLs ending at a highly congested location in Henry County and the prospect of trucks having to merge into the general-purpose lanes on I-75 North
  • Complete an independent assessment of impacts to traffic flow on I-75 North
  • Assess land use and transportation needs within a 2-mile radius of Exit 216 / SR 155
  • Create three traffic simulation models of traffic flow on I-75 from Exit 216 / SR 155 to Exit 227 / I-675:
    • Without the CVLs constructed (No Build)
    • With the CVLs constructed (Build – As Proposed)
    • With CVLs constructed as planned and extended to I-675 (Build – Extension)

Study Results

Croy Engineering presented their findings to commissioners at the August 1 meeting. In summary, they found the truck lanes will not create an adverse impact to northbound traffic flow between Bethlehem Road and state route 155. When comparing traffic flow without the truck lanes versus traffic flow after the lanes open, they found the following:

For the 2030 Build year simulation models, the reduction in travel time was approximately 1.5 minutes in the AM peak hour and 3 minutes in the PM peak hour. By the 2050 horizon year, the reduction in travel time is 4.5 minutes during the morning peak hour and 3 minutes during the afternoon peak hour.

I-75 Truck Lanes Impact Study Presentation, August 1, 2023

The proposed auxiliary lanes provide additional capacity. This yields a reduction in I-75 travel time. Secondly, projects like widening state route 155 will improve local traffic congestion. Georgia DOT has two projects to widen highway 155. The first phase, between I-75 and SR 42, expects to start road work in 2027. A second phase on the west side of I-75 would follow.

The new Bethlehem Road exit will also take pressure off state route 155. The exit looks to start construction in 2025. It should open in 2028.

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Extension to I-675?

On the question whether a northern extension of the lanes would aid traffic flow, the study found such extension would result in “even greater” travel time reduction. However, the study cautioned such extension could be prohibitively expensive. This is because of right of way constraints, impacts to existing bridges and construction costs. Croy Engineering recommends Henry County conduct a benefit to cost analysis if it wishes to further pursue the northern extension.

Land Use Effects

When considering development patterns, the study documented a foregone conclusion among residents: extensive new industrial development clustered in north Locust Grove. Upcoming developments represent about seven million square feet of space. This is in addition to projects already constructed today. This area is entirely within Locust Grove city limits.

The Bethlehem Road exit, when complete, will provide access from I-75 to this area. Locust Grove is also coordinating with Georgia DOT on projects along highway 42. More info about that should be out soon.

Featured image shows I-75 at State Route 155. Georgia DOT photo.

About Clayton 1445 Articles
Clayton Carte is the founder and owner of MHF News. He founded the site in 2017 to highlight transportation projects. Over time, he began covering other topics like new development so residents can best know what’s happening in our community.