Michigan left

Standard design on a wide median

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Grand Haven

[[File:MichiganLeftSigns.png|Two versions of signs posted along an intersecting road or street at an intersection.
Top: most commonly used; state of Michigan standard.<ref>

A no left-turn scheme at the intersection of Bonny Serrano Avenue

Michigan left is a type of road design and traffic control strategy that is widely used in the United States, particularly in the state of Michigan, from which it derives its name. This design aims to increase traffic flow and safety by reducing the number of left-turn conflicts. In a Michigan left, drivers wishing to turn left must first go straight or turn right onto the main road, then make a U-turn at a median crossover provided a short distance from the intersection. This article provides an overview of the Michigan left, including its design, advantages, disadvantages, and impact on traffic flow and safety.

Design and Operation

The Michigan left is characterized by the prohibition of direct left turns at an intersection. Instead, vehicles that intend to turn left must proceed through the intersection to a designated U-turn location, which is typically a median crossover situated 200-500 feet beyond the intersection. After completing the U-turn, the vehicle then approaches the intersection again and makes a right turn onto the cross street. This design can also accommodate pedestrian crossings and bicycle lanes with specific modifications to ensure safety and accessibility for all road users.

Advantages

The primary advantage of the Michigan left is the reduction in conflict points at intersections, which significantly decreases the potential for accidents. By eliminating direct left turns, the design simplifies signal phasing and reduces the number of light cycles needed to handle all traffic movements, thereby improving the overall efficiency of the intersection. Additionally, the Michigan left can lead to smoother traffic flow, reduced congestion, and shorter wait times at intersections.

Disadvantages

Despite its benefits, the Michigan left has some drawbacks. The design requires additional space for the U-turn lanes, which may not be available in densely built-up areas. Some drivers may also find the Michigan left confusing, especially those unfamiliar with the design, potentially leading to navigation errors. Furthermore, the increased distance traveled to complete a left turn may slightly increase travel time for some movements.

Impact on Traffic Flow and Safety

Studies have shown that intersections utilizing the Michigan left design have lower crash rates compared to conventional intersections, particularly those involving left-turn collisions. The design has been credited with improving traffic flow and reducing delays, making it a favored approach in areas where space permits its implementation. However, the effectiveness of a Michigan left can vary based on factors such as traffic volume, the presence of pedestrian and bicycle traffic, and the specific characteristics of the road.

Conclusion

The Michigan left is a testament to innovative road design aimed at enhancing traffic efficiency and safety. While it may not be suitable for all locations, its successful implementation in Michigan and other parts of the United States demonstrates its value as an alternative to traditional intersection layouts. As urban areas continue to seek solutions to traffic congestion and safety, the Michigan left offers a proven strategy worth considering.