Transportation Systems Management and Operations
Initiatives and Innovations
On a stretch of Interstate 10 between Tucson and Phoenix, sensors placed along the highway set off an alert: Dust, whipped up by gusting wind, is creating dangerous driving conditions.
Immediately, overhead electronic message boards alert drivers to the threat ahead. Programmable signs next to the highway show a speed limit reduced from 75 mph to as slow as 35 mph. Closed-circuit cameras allow staff at the Arizona Department of Transportation’s Traffic Operations Center in Phoenix to see the real-time conditions on the roadway, while in-pavement sensors report the speed and flow of traffic. Read more about the dust storm dust detection.
After completing a comprehensive study of wrong-way driving crashes on state highways and how technology may help reduce the threat, the Arizona Department of Transportation is planning a prototype project to use existing highway sensors to detect wrong-way vehicles and to alert authorities and other motorists. Read more about wrong-way drivers.
The Tunnel Maintenance Unit used innovation to solve a problem and add value. The tunnel emergency call phones being inoperable has been a chronic problem. The tunnel's original construction installed the phone jacks in the bottom of the call box enclosures. During the Deck Park Tunnel quarterly cleanings, water penetrates the call boxes and compromises the phone jack connections. The Tunnel Unit modified the boxes by mounting the jacks to a removable back panel. The jacks no longer sit in pools of water for extended periods of time and may now be maintained from the backside of the panel within the tunnel airshafts. This allows easy access to the phone jack for maintenance without closing traffic lanes and exposing the crew to traffic – improving both mobility and safety. The crew constructed the removable back panels using scrap aluminum from the ADOT Sign Shop.
The ADOT Sign Factory is adding conspicuity striping to the back of ADOT maintenance vehicles to increase safety for ADOT crews and the public on the highway. To date the Sign Factory has completed 72 trucks with more requests pending.
Bi-annual No Passing Zone Reviews ensure all passing zones on the Arizona State highways are setup per ADOT Traffic Guidelines and Processes, as well as the MUTCD which is issued by the FHWA. They are reviewed and updated as roadway changes occur. Changes in no-passing zones come from many different causes. These include, but are not limited to, new junctions, new alignments, brush growth or brush removal, new buildings, over-striping or under-striping, all of which may change the correct sight distance needed for safe passing.
The most common reason for Traffic Signal failure is lighting strikes. The Traffic Signal Shop is constantly trying to find innovative ways to protect all of ADOTs current cabinets by finding a surge protector that can withstand lighting.
In addition to helping ADOT track freeway conditions, these sensors provide the data used to estimate the travel times that drivers see on message boards above freeways. The data also helps ADOT and the Maricopa Association of Governments, the regional transportation-planning agency, make decisions about future freeway improvements.
Using electronic wires embedded in the pavement, the sensors have been used along many Valley freeways for years. The current project is installing additional in-pavement sensors as a more reliable replacement for acoustic devices that are mounted on poles.
This project is one way ADOT is working toward the agency’s continuous improvement goal of reducing congestion on freeways in metro Phoenix.
A meteorology graduate student from ASU’s School of Geographical Sciences and Urban Planning will work as an intern in ADOT’s Traffic Operations Center, helping crews respond rapidly to winter storms and other weather challenges to clear highways and potentially prevent closures.
ADOT, the Department of Public Safety, the Federal Highway Administration and the Maricopa Association of Governments worked together to launch the three-year pilot project to locate DPS troopers at the TOC. The average time taken to clear all freeway lanes at crash sites on Maricopa County freeways has been reduced by nearly one hour (54 minutes), despite a 23 percent increase in the number of freeway crashes.
ADOT is reducing the percentage of the 17,924 striping miles requiring annual re-striping through the use of more durable materials that last for 2-3 years or preformed tape that is not re-striped.