Ramp Meters

Southern Nevada’s freeway ramp meters are a successful joint project of the Regional Transportation Commission of Southern Nevada (RTC) and the Nevada Department of Transportation and they help to improve motorist safety and the flow of traffic on the freeway.  The RTC’s Freeway Arterial System of Transportation (FAST) division controls the Las Vegas Valley’s freeway ramp meters on U.S. 95, I-515 and I-15.  The ramp meters are traffic signals with only a red and a green light that control cars merging onto the freeway and they are consistently monitored by FAST to ensure that they do not create congestion on surface streets.

How do ramp meters work?
How do you use ramp meters?
Could traffic back up onto local streets?
Ramp meter benefits
Frequently asked questions

How do ramp meters work?
Computers and cameras on the ramp and freeway determine how quickly drivers may safely enter the corridor.  To do this, the equipment measures freeway traffic speed and volume and ramp traffic.

How do you use ramp meters?
Pull up to the white line

Drive your vehicle all the way to the white line painted on the pavement next to the ramp signal. Make sure you can see the signal, be alert as the signal will change more rapidly than a signal at an intersection.

Wait for the green light
When the signal turns green, one car per lane may drive along the ramp and merge safely onto the freeway.

Use both lanes where available
Some freeway entrance ramps have more than one travel lane and each lane is controlled by its own signal. Use both lanes if indicated and abide by the signal controlling your lane of travel.

Could traffic back up onto local streets?
Cars waiting at a ramp meter will not be allowed to back up onto local streets. If the ramp meter software senses a backup, the ramp signal cycle will be increased to allow cars to enter the freeway at a faster rate. If that is not enough to relieve the backup, the meter may be turned off.

NRS 484: Traffic Laws
Warning – Traffic violations may result in fines. Failing to stop at a ramp meter when it is in operation is a traffic violation similar to running a red light.

Ramp meter benefits
To understand the benefits of ramp meters, think about what happens when you merge onto an already crowded freeway. Many cars try to enter and merge at once. Drivers on the freeway are forced to slow down to let cars enter from the ramp, which result in sudden speed changes, backups and accidents.

Ramp meters are in use in more than 20 cities and 12 states. They have reduced rear-end and sideswipe collisions by more than 30 percent in some cities.

Travelers can anticipate an overall reduction in travel time with ramp meters as each driver waits slightly longer to enter the freeway, but freeway traffic is smoother and overall speed increases.

Frequently asked questions
Q. Why do we need to have traffic flow “managed?”

A. Overall, ramp meters and carpool lanes are important traffic management tools that reduce accidents and keep traffic flowing on the freeways. Management of the region’s transportation system is necessary with traffic congestion constantly increasing (100 cars are added to valley roadways daily). Without that management, there would be gridlock on our freeways and more accidents.

Q. How do ramp meters provide more safety?
A. Freeway accidents have been reduced due to ramp meters according to before-and-after studies. The Minnesota Department of Transportation conducted a study of freeway conditions with their ramp meters turned off. All 430 ramp meters in the Minneapolis/Saintt Paul area were turned off for six weeks in 2000 and there was a 26-percent increase in crashes with the meters off. Rear-end crashes increased by almost 15 percent, “run-of-the-road” crashes increased by 60 percent, and sideswipe crashes were up 200 percent. Research shows that most freeway accidents occur during stop-and-go traffic due to inattentive drivers. Ramp meters provide a smoother traffic flow, which minimizes stop-and-go traffic.

Q. What is the waiting time with ramp meters?
A.
Waiting time varies depending on how many cars are ahead of you on the ramp. In the slowest situation (a 13-second red and a two-second green cycle), four cars enter each minute on a specific lane. In the fastest situation, 15 cars enter each minute.

Q. Won’t congestion continue to increase during rush hours and at locations where these ramp meters are supposed to help traffic flow?
A.
Overall, congestion in Las Vegas will constantly grow and that is why the RTC developed a state-of-the-art traffic management system including the use of ramp meters. In addition, the RTC is developing new rapid transit options that will make it easy to travel throughout the las Vegas Valley.