Conceptual Layout

The intersection of Lapeer Road and S. Genesee Road was included in the early preliminary engineering phase with support from the City of Burton due to intersection operations and safety concerns. This intersection is included in the 153 intersections that passed the skim analysis for experiencing crashes correctable by a roundabout and is a secondary analysis Tier Two intersection.

During the skim analysis, it was observed that there were 13 angle crashes and two head on left turn crashes over the 5-year period. These crashes resulted in zero fatalities, one type A injury, two type B injuries, and six type C injuries at the intersection.

The intersection of Lapeer Road and S. Genesee Road is a four-way stop controlled intersection. Lapeer Road is an east/west road with two lanes in each direction. S. Genesee Road is a north/south road also with two lanes in each direction. All approaches of the intersection widen out from a singlelane to have a right-turn only lane and a shared through/left-turn lane. There are overhead flashing traffic signals (red) for traffic control for all approaches.  An aerial of the existing intersection can be seen in the photo above.

In the southeast quadrant of the intersection is the Lapeer Market. The northwest and southwest quadrants present an area of fields near residential homes. The northeast quadrant presents a residential home and a sidewalk going north and east. No other quadrants at the intersections have sidewalks. There are overhead utilities crossing the south and east legs. For utilities present at ground level, there is a fire hydrant in the northwest quadrant, drainage structures in the northeast, northwest, and southeast quadrants, and gas line markers in the southeast and south west quadrant.

An operational analysis of the no-build condition was completed for the intersection using the 2045 forecast traffic volumes. The results of the analysis for the future no-build condition reveals all approaches and movements of the intersection operate at LOS B during the AM peak hour. During the PM peak hour, the east and westbound approaches operate at LOS C and northbound operates at LOS D and southbound at LOS E.

The 95th percentile queue lengths were reviewed at the intersection and the results showed all approaches experienced a maximum queue length of 84 feet (5 vehicles) during the AM peak hour and 152 feet (10 vehicles) during the PM peak hour.

The operational results for future no-build conditions are presented in the table below.

The proposed roundabout configuration for the intersection of Lapeer Road and S. Genesee Road is a single lane circulating. The proposed single-lane roundabout configuration will not fit inside the existing right-of-way. Based on the concept design, additional right-of-way may be required in the northeast, southeast, and southwest. The proposed inscribed diameter for the concept roundabout is 110 feet. The driveway configuration for the Lapeer Road Market should be investigated due to the existing driveways closeness to the proposed roundabout entry/exit radius. A concept plan for the single-lane roundabout can be found in the slide above.

An operational analysis for the single-lane roundabout (build) condition was completed for the intersection using 2045 forecast traffic volumes. The results of the analysis for the roundabout (build) condition reveals all approaches and movements of the intersection operate at LOS A during the AM and PM peak hours.

The 95th percentile queue lengths were reviewed at the intersection and the results showed all approaches experienced a maximum queue length of one (1) vehicle during the AM peak hour and two (2) vehicles during the PM peak hour.

The operational results for future roundabout (build) conditions are shown in the table below.

A roundabout would be feasible at this location, although it may be costly due to the necessary relocation of the utilities. There also should be coordination with the Lapeer Road Market about their driveway configuration.

Opinion of probable cost were developed for a single-lane roundabout. The total probable cost is $1.25 million in year 2025 dollars. The probable cost includes a 20 percent contingency and 3 percent inflation. Not included in this fee are the potential costs to relocate any utilities to accommodate the proposed layout.

Potential funding sources for this improvement could include regular road improvement funding, safety funds, CMAQ, or an earmark. A TOR was computed with a result of 10.66.

For a complete breakdown of the estimate please review the full report below.