How Michigan Built a Super Highway Using Only U-Turns

Summary

The video discusses the inefficiencies and dangers of 'stroads'—roads that combine the functions of both highways and city streets. It highlights how Michigan’s Hall Road redesign, using a unique 'Michigan Left' approach, improves traffic flow and safety by eliminating left turns. The design reduces conflict points and traffic delays, resulting in a more efficient system. The video also explores how similar principles can be applied to redesign urban streets, improving safety, walkability, and overall livability while balancing traffic flow.

Takeaways

• 😀 Stroads are roads that attempt to combine the characteristics of highways and city streets, leading to inefficiencies and safety concerns.
• 🚗 The main issues with stroads are their danger due to high-speed limits and driveways, and their inefficiency caused by traffic signals and frequent stops.
• ⚠️ Stroads are dangerous because of the high number of conflict points, especially at intersections where left turns increase the risk of crashes.
• ⏱️ Traffic signals on stroads create delays due to multiple phases for straight and turning traffic, contributing to inefficiency.
• 🏙️ To improve stroads, one must decide if the road's purpose is to efficiently move vehicles or to be a more walkable, community-oriented street.
• 🚧 A freeway-like road design, with no intersections or driveways, ensures vehicles can move safely and efficiently but can be expensive and divide communities.
• 🛣️ The Michigan Left design allows for efficient traffic flow by eliminating left turns at intersections and using U-turns instead.
• 🚦 The Michigan Left system is efficient because it reduces the need for left-turn phases at traffic lights, speeding up traffic flow without additional delays.
• 🚙 Hall Road in Michigan handles over 80,000 cars per day due to its unique Michigan Left design, managing traffic more efficiently than typical roads.
• 🚶‍♂️ Improving roads to create safer, more livable spaces involves slowing traffic, reducing access points, and promoting walkability, as seen in a redesign near Portland.

Q & A

What is a stroad and why are they considered problematic?

A stroad is a type of road that attempts to combine the functionality of both a highway and a city street. It aims to move vehicles quickly like a highway but also has businesses and driveways like a city street. The problems with stroads are that they are dangerous due to the high number of conflict points (driveways and intersections), inefficient because of traffic signals, and prone to severe crashes due to high speed limits.

Why are traffic lights and phases problematic on stroads?

Traffic lights and phases on stroads create inefficiency by slowing down the flow of traffic. These intersections typically have multiple phases for straight traffic, right turns, and left turns, which results in long waits for vehicles to clear the intersection. This causes delays and reduces the overall efficiency of the road.

How does the Michigan Left improve traffic flow on roads like Hall Road?

The Michigan Left improves traffic flow by eliminating left turns at intersections and instead redirecting drivers to turn right and then perform a U-turn to access the opposite direction. This allows traffic to flow in the same direction without interruption, making intersections more efficient and reducing delays caused by left turns.

What are the advantages of eliminating left turns in traffic design?

Eliminating left turns reduces conflict points, which are locations where vehicles cross paths, making them a common cause of crashes. It also makes it easier for drivers to find gaps in traffic and reduces stress by allowing drivers to focus on only one direction of traffic at a time, leading to safer and quicker maneuvers.

How does the Michigan Left design impact traffic signal phases?

The Michigan Left design allows for a simplified traffic signal system. Since there are no left turns, only two phases are needed for traffic to go straight or turn right. This reduces the time spent waiting for left turns and leads to smoother, faster traffic flow through the intersection.

What makes Hall Road in Michigan unique compared to other roads?

Hall Road is unique because it functions as a high-traffic corridor similar to a freeway but without grade-separated exits. It uses the Michigan Left design to handle over 80,000 cars per day efficiently by directing traffic through right turns and U-turns, avoiding left-turn conflict points and reducing delays.

What are the safety benefits of the Michigan Left design?

The Michigan Left design improves safety by reducing left-turn conflicts at intersections, which are typically the riskiest maneuvers. It also decreases the number of conflict points and lowers the chances of accidents. Additionally, the continuous flow of traffic reduces the likelihood of rear-end crashes caused by stop-and-go traffic.

Why is the design of Hall Road not perfect, despite its benefits?

While Hall Road improves efficiency and safety, it still has drawbacks. It is a high-speed, multi-lane roadway that can lead to serious accidents despite efforts to reduce conflict points. It also takes up a large amount of space, which may not be ideal for areas looking to prioritize walkability and community interaction.

How can streets be redesigned to promote walkability and safety?

To promote walkability and safety, streets can be redesigned by limiting access points, reducing vehicle speeds, and using design elements like roundabouts. These changes help reduce conflicts and make the street more pedestrian-friendly. By prioritizing street-facing businesses and creating public spaces, the road can become a vibrant and livable area.

How do roundabouts contribute to safer and more efficient streets?

Roundabouts help by slowing down vehicle speeds, which improves safety for all road users. They also allow for continuous traffic flow without the need for multiple stop phases, reducing delays and making it easier for drivers to access side streets. Roundabouts can also accommodate U-turns, further enhancing traffic management.