Tag Archives: traffic management

A google doodle with a Utah link

Whether you’re sitting at a red light or passing through on green, the traffic signal is one invention that revolutionized the world. And because of that, Google has taken to honor the anniversary of the first installation with a “doodle”.

August 5, 2015's Google Doodle

August 5, 2015’s Google Doodle

On August 5, 1914, the first traffic light was installed in Cleveland, Ohio, on the corner of 59th and Euclid. With 20,000 cars being sold per month in 1914, and horse-drawn wagons, street cars, and carts still in play, city streets in America were woefully congested, and a need arose for traffic management. Police used to stand in the middle of intersections and wave their arms to control traffic, and just before the turn of the century, England tried a gas-lit stoplight, but they had a tendency to explode.

But what does that have to do with Utah?

One of the solutions to the traffic management problem came when Lester Wire — a Salt Lake City policeman — created a traffic light out of a hand-made wooden box that had red and green lights whose wires were attached to light wires above. Right in the Beehive State, a solution was born. 

This replica of Lester Wire's first traffic light greets visitors to the UDOT Traffic Operations Center.

This replica of Lester Wire’s first traffic light greets visitors to the UDOT Traffic Operations Center.

We’ve come a long way since 1914, and UDOT is proud of what our employees at the Traffic Operations Center have done to create a state-of-the-art traffic management system. Instead of mechanical lights and wooden boxes, we use sophisticated computers that gather traffic and weather data to manage 60% of the 1,927 traffic lights statewide. We use that information to give you the best data, sent right to your smart phone, and we also have one of the few in-house DOT weather rooms, staffed with two full-time meteorologists and 8 weather professionals.

Next time you’re sitting at a red light or passing through on a green light, you can thank a fellow Utahn for coming up with a traffic solution. Thank you, Google, for giving us a chance to walk down memory lane!

First yellow flashing right turn arrow arrives in Utah

LEHI — Northern Utah County is developing at a rapid pace, emerging as a new frontier of the high-tech industry. In addition to retail attractions such as Cabela’s and the Outlets at Traverse Mountain, the area around I-15 at Timpanogos Highway (SR-92) has been dubbed the “Silicon Slopes,” attracting businesses who want affordable office space, a reliable talent pool from area universities and the high quality of life Utahns enjoy with a variety of outdoor recreation options just minutes away.

With all this development, UDOT continually evaluates how to improve traffic flow through the I-15/SR-92 interchange.

The latest update to the interchange is also a first in Utah: crews installed the state’s first flashing yellow right turn arrow at the northbound I-15 off-ramp to eastbound SR-92 in Lehi. You have probably driven through dozens of flashing yellow left turn arrows, where turning traffic yields but may make a left if there is no oncoming traffic. So why does the flashing yellow right turn arrow work at this interchange?

A flashing yellow arrow on a right hand turn on SR-92 allows traffic to flow more freely in a fast-growing part of Utah County.

A flashing yellow arrow on a right hand turn on SR-92 allows traffic to flow more freely in a fast-growing part of Utah County.

 

“The right turn goes into a lane that takes people to the SR-92 commuter lane, but a lot of people want to make a left into Adobe or Cabela’s,” said UDOT Region Three Signal Engineer Adam Lough. “We were seeing traffic back up and drivers getting frustrated because people who wanted to cross traffic to get to the left lane would be stopped on a green light. The flashing yellow signals a yield condition for drivers who want to move to the left lane on SR-92 as well as for the queue of traffic on the ramp.”

Now when the light is green, there is no eastbound traffic for drivers to weave through to move left; and during the flashing yellow, drivers who want to move left must wait for a safe opening in the traffic flow. Drivers who want to access the SR-92 commuter lanes from the I-15 northbound off-ramp still get impatient at times, but Lough said the flashing yellow right turn arrow has improved the traffic flow. “This provides a safer condition and has reduced the amount of backing on the ramp.”

Lough developed the idea of using a flashing yellow right turn arrow to address the traffic problems at this interchange ramp. Although UDOT had never installed anything like it, Lough suggested that it would be the best solution and worked with Traffic Operations Center staff to implement it. So far, he is pleased with the results.

“I am always looking for better ways to do things,” he said. “It is rewarding to see how changes like this make people’s commute a little better.”

Lough said the signal is almost always green or flashing yellow, but it briefly turns solid yellow and red as part of the signal’s cycle. The pedestrian button also triggers the red arrow.

“There is quite a bit of pedestrian traffic between the employment centers and retail outlets on either side of I-15 in this area,” Lough said. “Drivers really need to be on the lookout for pedestrians and bicyclists moving through this interchange.”

Riding along for traffic data

You’ve used the app. You’ve seen the traffic cameras on TV or online, and you might have even seen the Traffic Operations Center in person. But have you ever wondered what exactly goes into getting the information? We’ll take you on a “ride along” and show you how.

Through the technology and data of the Advanced Traffic Management System (ATMS), UDOT can Keep Utah Moving. Recently, a critical part of the system was updated along the I-15 corridor, as newer controllers were installed and programmed. The controllers gather volume and speed data from passing vehicles. Although no identifying information is collected, it does give a wealth of data on the speed of traffic, the density of traffic, weather conditions, etc.

The replacement process starts when the new lane controllers are programmed with the proper software to collect the data. The controllers run on Linux-based command prompts and also use custom software add-ons. The base software is programmed at the UDOT Traffic Operations Center.

Kent (left) and David (right) are in charge of maintaining and upgrading the ATMS systems along the Wasatch Front.

Kent (left) and David (right) are in charge of maintaining and upgrading the ATMS systems along the Wasatch Front.

Once the controllers are programmed, they are ready to be deployed into the field. The first set to be replaced was along southbound I-15 at 3300 South.

Kent and David working in an ATMS cabinet alongside I

Kent and David working in an ATMS cabinet alongside I-15.

The new controllers are wired in and turned on. They also have to be programmed once they are in the cabinet by using data from a controller at a different location. This process requires time, patience and many command prompts.

atms crew 3

The lane controllers are installed as a pair, in case one fails while in the field. One acts as the primary and one as a secondary. They both have ability to function independently, but also as a pair.

Once the new controllers are field-programmed, they are brought online and tested to make sure that they are working properly. Once they are tested and confirmed to be working, the ATMS crew moves on to calibrate and install the next set of lane controllers. The whole process of removing the old boxes and installing and testing the new ones takes just under an hour per cabinet.

An overhead sensor that collects data from Express Lane users.

An overhead sensor that collects data from Express Lane users.

UDOT also uses in-pavement “pucks” that collect traffic data. All of this information is sent to a nearby traffic cabinet and then to the UDOT Traffic Operations Center. The information is used to create the congestion layers on the UDOT Traffic app and website, so travelers can know about delay and congestion information for their trips.

An in-pavement "puck" that collects speed data from passing vehicles.

An in-pavement “puck” that collects speed data from passing vehicles.

This guest post was written by Adam McMillan, Traffic Operations Center Intern.