"Rest in red" traffic safety technology

A view of two red traffic signal lights from below on a foggy night.
Explainer from the Portland Bureau of Transportation) about “rest in red” technology for traffic signals. How the technology works, how it’s deployed, what it costs. Information provided by PBOT’s Traffic Systems & Operations group and Vision Zero team.
On this page

"Rest in red" explained

"Rest in red" is a traffic signal timing operation with enhanced technology that Portland Bureau of Transportation (PBOT) uses to manage travel speeds and make signals more responsive to people walking, biking, and rolling. PBOT is  using "rest in red" technology to help target and interrupt dangerous driving behavior—such as excessive speeding on wide, open corridors during late night and early morning hours—which contributes to deadly crashes.

Traffic signals with “rest in red” technology can display red lights in all directions during late night and early morning hours when traffic volume is light rather than cycling through green, yellow, and red the way they do normally during the day.

When a person driving a vehicle approaches a “rest in red” intersection, the traffic signal may stay red until it detects that the driver reached the intersection. Assuming no cross-traffic is approaching, the traffic signal will turn green to benefit people that are driving within the speed limit.

Encouraging safe travel speeds

Installing "rest in red" traffic safety technology is a way to encourage safer travel speeds, which is a top contributing factor to traffic safety. Speed was reported to play a role in at least 42% of deadly crashes between 2017 and 2021. This includes both driving over the speed limit and driving too fast for road conditions. As people travel faster, the risk of death or serious injury rises dramatically. For example, a pedestrian struck by a person driving 40 mph is eight times more likely to die than a pedestrian struck at 20 mph. Safe speeds lower the risk of crashes. And when crashes do occur, safe speeds make it less likely that people will be seriously injured or killed.

Review Portland's annual deadly traffic crash report to learn how speeding contributed to the previous year's deadly traffic crashes.

Other traffic signal technology examples

PBOT uses other types of traffic signal technology to encourage safe travel speeds. For example, if a person drives 13.5 mph downtown, they are more likely to catch green lights and travel in groups with other vehicle traffic.

Similarly, PBOT has deployed special signal timing along N Vancouver Avenue so people biking don’t repeatedly get stopped by red lights.

“Rest in red” in other cities

PBOT has looked at other cities that have deployed “rest in red” technology. One example is Albuquerque, New Mexico which implemented "rest in red" traffic safety technology in 2023 and saw a reduction in speed. Los Angeles, California has also used this technique in the past.

Designing and maintaining streets to protect people

The Vision Zero Action Plan Update 2023-25 includes "rest in red" traffic safety technology as one of the actions and performance measures to maximize signal operations and to design and maintain streets to protect people—even when they make mistakes. Core to this work is slowing down people driving and protecting people outside vehicles.

Portland locations

Existing location

Future locations

  • SE Powell Boulevard: PBOT plans to install, test, and evaluate "rest in red" traffic signals along SE Powell Boulevard—one of Portland's highest crash streets with a history of speed-related crashes. In coordination with the Oregon Department of Transportation, which is responsible for SE Powell Boulevard (US-26), PBOT will upgrade signals from 21st to 33rd avenues near Powell Park, Cleveland High School, and the Cleveland High School track and sports field. These upgrades are slated for summer 2024.
  • 82nd Avenue: PBOT will upgrade existing signals and install new ones along 82nd Avenue in 2025 to implement "rest in red" traffic safety technology without needing to identify additional funding.

PBOT will likely be adding more locations over time when we upgrade traffic signals as part of larger capital improvement projects when warranted. 

How the technology works


At most traffic signals, PBOT uses smart sensors to detect approaching cars to determine when to give a green light. PBOT currently uses "microwave detection" mounted on traffic signal mast arms. "Microwave detection" can locate approaching traffic from several hundred feet away.

Signal controllers

Signal controllers are the "brains" of the traffic signal that make "rest in red" work. During peak hours, signal controllers collect and communicate important information. During off-peak hours, signal controllers with the right detection can allow for different types of operation to minimize speeding.

Newer traffic signals are more likely to include smart detection technology and upgraded signal controllers. However, many traffic signals across the city are aging out and have limited or no detection as well as signal controllers which haven’t been upgraded.

PBOT plans to update traffic signals as needed and funding becomes available to match city policy.

Cost and funding

The cost to install "rest in red" technology can range from about $20,000 to $100,000 per intersection, depending on the state of the existing system. First, older traffic signals need to be updated with detection and signal controllers as described above. Second, signals which are newer, or which have been updated to have "rest in red," require staff time to retime and evaluate them.

PBOT is paying for the initial implementation of "rest in red” on SE Powell Boulevard with operational funds from the City of Portland’s cannabis tax. PBOT is updating other locations, such as 82nd Avenue, through Capital Improvement Projects funding.