In 2017, 939 people were killed in collisions caused by motorists running red lights—a 10-year high.
One year later, the number was down, but not enough. On average, two to three people are still killed every day by red light runners, and another 139,000 people are injured. Agencies across the country are pursuing the best technology and the most proven solutions to stop red light running.
Beyond merely punishing offenders, actually curbing behavior starts by understanding why and how drivers run red lights. Effective solutions can then be engineered by combining:
- The latest technology — The most effective technology available for stopping red light runners is the Iteris Vantage Vector Hybrid all-in-one detection sensor.
- Engineering best practices — Analysis of driver behavior and environmental conditions provide insights on how to enable drivers to avoid running red lights.
The Cost of Red Light Running: Statistics and Facts
In 2018, 846 people were killed in crashes that involved red light running. About half of those killed were innocent bystanders—pedestrians, cyclists, and people in other vehicles—hit by the red light runners.
Red light running is a serious issue for agencies across the country:
- 56% of drivers admit to occasionally running red lights.
- 43% of drivers admit to having recently run a red light when they could have stopped safely.
- 1 in 3 Americans witness red light running “fairly often.”
Why Motorists Run Red Lights
There are a variety of factors that may contribute to a motorist running a red light—from personal habits and demeanor, to environmental circumstances. For example, drivers will often run red lights when they feel the car in front of them took a bit too long to proceed through an intersection, or when they think they can “beat the yellow” but misjudge the timing.
A majority of people run red lights because they’re in a hurry or feeling impatient. Although common, this reflects a fundamental miscalculation of risk and reward. Are the few minutes potentially saved by running the light worth the potential of causing a terrible accident? Absolutely not.
Some drivers also run red lights because they simply cannot stop in time. In other words, their red-light violations result from a separate violation: speeding. Speeding reduces the time a driver can make the decision to stop, which in turn leads to a higher risk of running a red. Speeding puts drivers in the difficult position of having to gauge whether it is better to slam on the breaks (which poses a new set of dangers to those following) or to run the light hoping there isn’t any conflicting traffic. Drivers must make this decision in the blink of an eye, and getting it wrong can result in catastrophe, unless technology can be placed at the intersection to help mitigate these situations.
The Dilemma Zone
The dilemma zone is the stretch of road, on approach to the stop bar, wherein a motorist can neither stop nor proceed safely. Attempts are sometimes made to assign measurements to the start and end of the dilemma zone, but the effective dilemma zone varies for each driver based on driving speed, reaction time, comfort level, perception of surrounding conditions, etc.
Long and short yellow lights increase complexity in the dilemma zone. Short yellow lights put too many drivers over the stop bar after their signal has turned red. Signals that stay yellow for too long, however, increase the time that cross-traffic sits at a red light, encouraging motorists to speed through yellow lights to avoid the wait.
Inattentive or distracted driving is one of the main reasons that motorists accidentally run red lights. Smartphones, radio, GPS, passengers, and drowsiness have all been cited as factors for red light running.
- 57% of drivers report eating or drinking while driving.
- 29% of drivers admit to texting while driving.
- 41% of drivers admit to having fallen asleep behind the wheel.
Following a Large Vehicle
At least one study has noted a statistical increase in the rate of red light running when a motorist is following an oversized vehicle, as compared to following a passenger car. The report suggests that the traffic signal in those cases is not sufficiently visible.
A variety of environmental conditions increase the likelihood of red light running as well. Inclement weather makes motorists less likely to hit the brakes in the dilemma zone, causing them to run the red light.
Drivers are also more likely to run red lights:
- During peak AM and PM hours.
- When the approach to the signal is on a downgrade.
How to Stop Red Light Runners: Solve the Dilemma Zone
Traffic engineers have long known that the best way to reduce red light running is to solve the dilemma zone … but how?
Non-tech solutions, like experimenting with the length of the yellow light, may reduce the frequency of red light runners, but take some trial and error to establish. Traditional technical tools, like red light cameras and loop detector treatments, were more sophisticated solutions, but could never account for every driver.
One of the best ways to solve the dilemma zone—for every motorist approaching an intersection—is the Iteris Vantage Vector Hybrid. The Vantage Vector system combines video and radar to detect and account for every motorist approaching an intersection.
As a vehicle crosses five user-defined trip lines, the Vector sends outputs to the controller with required extension times. If a driver is slowing, the Vector can calculate if and when they will safely come to a stop. If a driver is accelerating toward a yellow light, the Vector can determine how long the yellow light should be extended to allow that vehicle to safely clear the intersection.
In addition to providing the only complete dilemma zone solution, the Vector is:
- Efficient — The non-intrusive system is easily installed with no trenching required.
- Adaptable — The system includes bicycle detection and differentiation, as well as pedestrian measurement and volume.
- Compatible — The Vector works with Siemens Traffic Controller’s and TACTICS.
Supplemental Strategies for Stopping Red Light Runners
Additional, more traditional, solutions have been used to reduce red light runners. Many of these can be used in conjunction with a system like the Vantage Vector to help motorists better navigate intersections.
1. Improve Awareness
Inattentive drivers often run red lights simply because they didn’t know the intersection was coming. There are several ways to improve awareness of an approaching intersection, so drivers can tune in and be prepared to respond to signal changes:
- Install Signal Ahead signs to alert drivers of a signal, especially if it is not clearly visible on approach.
- Implement rumble strips to enhance awareness through audible and tactile warnings. Note that rumble strips are not recommended where there is heavily bicycle traffic or where noise will disturb a residential community.
- Use activated advance warning flashers to alert drivers when a downstream signal is, or is about to turn, yellow or red. These can be flashing beacons that activate or a message that reads, “Red Signal Ahead,” placed at an appropriate distance for the speed zone.
- Optimize road conditions by repainting markings, ensuring that lanes and warnings are clear, improving skid resistance on the asphalt, etc.
2. Improve Signal Visibility
Poor signal visibility is another common reason for accidental red light running, and should always be addressed. Improving signal visibility can result in 25% fewer red light runners.
- Replace pole-mounted signals with overhead signals to improve visibility, especially where oversized vehicles may block a motorist’s view of the pole-mounted signal.
- Position one signal above each approach lane. Intersections with one signal over each lane have the lowest rate of crashes.
- Install backplates to improve the visibility of each signal. Backplates are especially helpful in urban environments with visually complex landscapes. Additionally, retroreflective signal backplates have been demonstrated to reduce crashes by 15% and to reduce late night/early morning crashes by 50%.
3. Adjust Signal Timing
Adjusting signal timing to stop red light runners is an art and a science. Some trial and error may be required to find the best timings—and no static timing will ever be able to address every motorist—but some adjustments may prove beneficial:
- Extend yellow lights by one second. An extra second on yellow lights correlates to 53% fewer red light runners, although there are usually diminishing returns beyond an extra 1.5 seconds.
- Add an all-red clearance interval to account for motorists who will still run red lights, and allow them to clear the intersection. These intervals are usually between 0.5 and 3 seconds long, but be careful not to extend red lights beyond public tolerance.
4. Eliminate the Need to Stop
In very difficult situations, it is sometimes possible to eliminate the need for motorists to stop at an intersection.
- Convert the intersection to a roundabout. Roundabouts generally achieve a 75% reduction in injury collisions and a 90% reduction in fatality collisions. It does, of course, take a heavy investment in resources to convert an intersection.
Improve Safety and Stop Red Light Running
The frequency of fatal red light running accidents has finally started to decline in recent years, but the numbers are still much too high. Enforcing laws by issuing tickets is one way to discourage red light running, but a truly effective solution for improving safety on the roadways needs to be more thorough.
There are dozens of tactics that engineers can experiment with to improve awareness and visibility, and optimize roadways and intersections, but none of these solutions can account for the myriad of conditions that apply to each individual driver.
The Vantage Vector Hybrid, however, does consider each vehicle that approaches a signal, to stop red light running and ensure the safety of motorists, cyclists, and pedestrians at a given intersection. To learn more about this innovative system, contact Western Systems online or give us a call at 425.438.1133.