Freakonomics Radio
Should Traffic Lights Be Abolished? (Ep. 454 Replay)
Description
The episode explores the benefits and challenges of roundabouts as a safer and more efficient alternative to traditional intersections. It discusses the high number of traffic crashes and fatalities at intersections controlled by traffic lights, highlighting the potential lives that could be saved by swapping them out for roundabouts. The case study of Carmel, Indiana showcases the success of roundabouts in reducing fatalities and improving traffic flow. The chapter also delves into the costs and economic benefits of roundabouts, as well as public perception and acceptance of these circular intersections. The episode concludes with insights on the challenges faced by autonomous vehicles in navigating roundabouts.
Insights
Roundabouts can save lives
Swapping out standard intersections with traffic lights for roundabouts could potentially save thousands of lives in America.
Carmel, Indiana leads in roundabout construction
Carmel, Indiana has built more roundabouts than any other city in North America, significantly reducing fatalities and improving traffic flow.
Roundabouts are cost-effective
Converting standard intersections to roundabouts may have higher upfront costs but pays off in the long run through reduced maintenance and improved traffic flow.
Public perception plays a role
Resistance to roundabouts may stem from fear of change and risk-taking by elected officials, but acceptance tends to increase once people become familiar with them.
Roundabouts and autonomous vehicles
Navigating roundabouts is a challenge for both human drivers and autonomous vehicles, but advancements in technology are enabling autonomous vehicles to safely navigate these intersections.
Chapters
- Roundabouts and Traffic Safety
- Roundabouts in Carmel, Indiana
- Safety and Benefits of Roundabouts
- Costs and Benefits of Roundabouts
- Benefits and Challenges of Roundabouts
- Roundabouts and Autonomous Vehicles
Roundabouts and Traffic Safety
00:04 - 08:01
- Many crashes and traffic injuries happen at intersections controlled by traffic lights.
- Roundabouts are small circular traffic intersections without traffic lights or stop signs.
- Swapping out standard intersections with traffic lights for roundabouts could potentially save thousands of lives in America.
- Roughly 40,000 Americans are killed each year in traffic crashes, with about a quarter of those deaths happening at intersections.
- Crashes also cause millions of injuries and over a third of a trillion dollars in property damage and costs.
- Roundabouts have economic benefits, lower emissions, but may present technical complications at entrances.
Roundabouts in Carmel, Indiana
07:43 - 15:06
- Carmel, Indiana has built more roundabouts than any other city in North America.
- There are currently 133 roundabouts in Carmel, with more under construction.
- Carmel accounts for nearly 2% of all roundabouts in the US.
- Roundabouts have a lower fatality rate compared to other types of intersections.
- Roundabouts force drivers to slow down, reducing the risk of accidents.
- Roundabouts are safer for pedestrians and people with disabilities.
- Roundabouts save money by replacing stoplights.
Safety and Benefits of Roundabouts
15:00 - 22:28
- Roundabouts are safer than intersections with conflicting traffic flows.
- Carmel, Indiana has significantly fewer fatalities due to roundabouts.
- The UK has a high number of roundabouts and a lower rate of traffic fatalities compared to the US.
- Red light cameras can make intersections safer by reducing drivers rushing to make the light.
- Converting standard intersections to roundabouts reduces fuel consumption and carbon emissions.
- Roundabouts improve traffic flow and reduce congestion compared to signalized intersections.
- The cost of building roundabouts is higher than signalized intersections.
Costs and Benefits of Roundabouts
22:04 - 29:31
- Roundabouts can be more expensive than signalized intersections, especially when converting existing intersections due to factors like real estate and retrofitting difficulties.
- Signalized intersections can cost anywhere from $250,000 to over a million dollars.
- Material costs and labor costs make up about 50% each of the total cost of a signalized intersection.
- Signal heads, which contain the red, yellow, and green lights, can cost around $2,000 to $3,000 each.
- Poles that support the signal heads can cost around $25,000 each and take up to 10 months to obtain due to engineering requirements.
- The control box in an intersection costs around $30,000 and serves as the brains of the operation.
- Electrification costs vary depending on circumstances but can range from $3 per foot to $100 per foot for wiring alone.
- Pedestrian push buttons at crosswalks can add another $20,000 per signalized intersection.
- Maintenance and repair are necessary for traffic signals due to various issues like hurricanes or rats damaging equipment.
- LED bulbs have been a major innovation in recent years as they reduce electricity bills but may not produce enough heat in winter states like Illinois or Minnesota.
- Traffic signals account for about two billion dollars in lost time annually due to delays at intersections.
- Converting a four-way stop into a roundabout is generally less expensive than adding traffic lights.
Benefits and Challenges of Roundabouts
29:17 - 36:59
- Building a roundabout is cheaper than adding traffic lights to an intersection in Indiana.
- Converting an intersection with traffic lights to a roundabout has short-term costs but pays off in the long run.
- Converting to a roundabout may require additional land and moving underground utilities.
- Roundabouts can increase commercial access by improving traffic flow.
- Roundabouts can move 50% more cars per hour compared to stoplights.
- There is a growing movement in the United States to build roundabouts, with incentives in federal transportation law and encouragement from state DOTs.
- Resistance to roundabouts may be due to fear of change and risk-taking by elected officials.
- Some cities have faced public opposition or concerns about driving behavior when considering roundabout projects.
- The popularity of roundabouts in Europe may contribute to their perception as foreign or unfamiliar in the US.
- Drivers' apprehension towards roundabouts tends to decrease once they become familiar with using them properly.
Roundabouts and Autonomous Vehicles
36:33 - 44:22
- Navigating roundabouts is a challenge for both human drivers and autonomous vehicles.
- Autonomous vehicles use algorithms to negotiate roundabouts by detecting objects, extracting metadata, and playing forward different scenarios to choose the safest option.
- Public acceptance of autonomous vehicles may be a challenge due to anxiety and perception hurdles.
- Change is often opposed initially but eventually accepted when it becomes inevitable.
- Roundabout acceptance happened relatively fast after people became familiar with them.
- English roundabouts often reflect local culture through sculptures and artwork, while American roundabouts have more potential for creativity.