January 22, 2008
The Arizona Department of Transportation (ADOT) launched a test program for travel times on freeways in the Phoenix metropolitan area. (The freeway system in the vicinity of Arizona’s capital is one of the largest and fastest-growing networks of its kind in the entire United States.)
ADOT’s pilot project involved using a select number of dynamic message signs (DMS) to display estimated times on how long it would take drivers to reach popular commuter destinations in that part of Arizona. Initially, these travel times were made available on the most heavily used corridors in the Phoenix area and on weekdays during peak hours in the morning (6:00 a.m. to 9:00 a.m.) and afternoon/evening (3:00 p.m. to 7:00 p.m.). This travel information would not appear on any DMS if there was a need to instead publicize emergency notifications such as AMBER Alerts.
In initiating the electronic display of freeway travel times on an experimental basis, ADOT joined the ranks of other state departments of transportation that have likewise harnessed DMS for announcing estimated intervals between different points along highways. The Georgia Department of Transportation started posting travel times on DMS in 1998 for drivers in the Atlanta area, for example, and the Utah Department of Transportation launched its own DMS test program for travel times in 2005 in the vicinity of Salt Lake City.
Within just a few years, the overall reaction to the use of DMS for travel times in the Phoenix area proved to be highly positive. This was confirmed by James Minton, a shift supervisor at the ADOT Traffic Operations Center, during a 2014 interview for the department’s blog. “A lot of people appreciate the system,” said Minton. “People have really responded well.” By 2015, the travel times on display on Phoenix-area DMS had been extended for the periods from 5:00 a.m. to 11:00 p.m. on weekdays and from 7:00 a.m. to 9:00 p.m. on weekends.
Another example of this ever-expanding use of DMS within the Grand Canyon State took place towards the end of 2019 when ADOT began using message signs on Interstate 10 (I-10) to post likely travel times between Phoenix and Arizona’s border with New Mexico. “It’s great to expand travel time displays along I-10, especially ahead of the holiday travel period,” noted ADOT Director John Halikowski in a press release issued by the department in December 2019. “I-10 is one of the state’s busiest key commerce corridors, so we want to provide drivers with information that can help with their highway travel.”
Brent Cain, director of ADOT’s Transportation Systems Management and Operations Division, underscored these benefits in his own comments on the extension of DMS for travel times to other parts of Arizona. “We’re pleased to be able to provide estimated travel times to drivers in rural areas of the state,” he said. “Technology has come a long way in the past decade. We’re giving more drivers a better idea of highway conditions up ahead, especially if they see a longer than normal travel time posted.”
Additional information on the use of dynamic message signs for posting travel times in Arizona is available at https://azdot.gov/sites/default/files/2019/06/adot-dms_traveltimeevaluation-finalreport.pdf and https://azdot.gov/adot-news/adot-displays-more-travel-times-along-interstate-10
For more information on freeways in the Phoenix metropolitan area, please check out https://en.wikipedia.org/wiki/Roads_and_freeways_in_metropolitan_Phoenix
Transportation History 
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