Pitu Mirchandani, a professor of systems and industrial engineering, says RHODES won't rely on the typical predetermined mechanisms usually used to set green time for traffic signals. Instead, employing new technology, it will look at the length of wait and size of automobile queues at one intersection in order to predict when and how many cars will be arriving later at another intersection. This information, he believes, will allow the signal system to be used to its optimum in order to minimize delays.
Tucson's top traffic engineer, Richard Nassi, has high hopes for RHODES. "It's almost as good as an additional lane of traffic," he says enthusiastically in comparing it to a $10 million-a-mile roadway widening project. "But the cost of RHODES will be minimal because we're using existing control equipment and cameras."
Relating how traffic engineering got its start in 1914 New York City with strategically placed police officers connected by telephones, Nassi concludes, "What the people at the university have designed is an electronic cop using artificial intelligence."
A similar pilot program done in Chicago and reported in a recent issue of Discover magazine showed promising results. Based on findings there, researchers predicted that traffic delays could be decreased by 6 to 8 percent because of the improved technology.
SMARTER intersections aren't the only technological advance on the horizon. Early next year a "Freeway Management System" should be installed along I-10 and I-19. This project will include both a series of television cameras and eight message boards to gather and relay traffic and accident information.
In addition, traffic planners are hoping within a few years to institute a freeway service patrol similar to one presently found in Phoenix. These patrols would aid motorists with flat tires, overheated radiators and other minor problems with the goal of removing the stranded vehicle from the interstate as quickly as possible.
One future use for the freeway monitor boards may also be to encourage drivers to slow down so all traffic will move faster. The concept is that a slower but steadier flow of automobiles will progress more smoothly than a mass of vehicles moving at various speeds. According to Discover magazine, "[Researchers] have found that reducing the speed limit to about 50 miles per hour on German highways when congestion increases can reduce delays by 30 percent."
This theory was tested in Tucson many years ago. Small message boards were posted along 22nd Street, encouraging drivers to move at a uniform rate of speed in order to decrease congestion. But as traffic engineer Nassi relates, "The signs worked but drivers didn't embrace them by going the indicated speed. Instead, they would drive at or above the speed limit to the next red light." The test program was eventually determined a failure, and the signs removed.
Other Tucson technological programs, however, have had more success. The city was a leader in introducing lagging left-turns in 1984 and is still improving the system. One of the few leading-left signals still remaining in town, at the intersection of Tanque Verde and Sabino Canyon roads, will soon be switched thanks to improved mechanics developed in Texas.
Nassi also indicates that drivers have mostly understood the solid and then flashing red lights at the HAWK (High Intensity Activity Crosswalk) pedestrian crossings scattered along major streets around town. The city's traffic engineer adds, however, "Some drivers are unsure of what the flashing red means. They should treat it like a stop sign when it's flashing." He expects 24 more of these signals to be in operation within four years. Nassi also anticipates that a few more toucans and pelicans, those specialized bike- and pedestrian-activated crossings, will be built in the near future.
Another expected technological improvement is a new system to improve emergency medical care. The process will allow two-way voice, video and medical statistical communication between an ambulance and hospital. On September 4, the City Council was asked to accept a $994,000 federal grant to initiate the program, which, Nassi says, "extends the emergency room into the ambulance." He thinks the system could be operational within two years.
One other small but significant change involves traffic signals. The city currently pays almost $2 million a year to operate signals and street lights, but they are looking into using solar-powered signals with a battery backup. Nassi hopes within a year to have fire station and other periodic signals solar-powered, with a five-year goal of possibly using the sun to light all of Tucson's 350 traffic signals.
An ancient traffic program Nassi doesn't believe will change is the reversible lane on Grant Road, started 20 years ago as a "temporary measure." Because of existing traffic volumes he doesn't see the Grant Road reversible program disappearing anytime soon, unlike the rush hour lanes once found along Fifth/Sixth Street, Speedway and Broadway.
But while this low-tech, aggravating traffic program may continue on Grant Road, advanced technology in the future should help ease some of Tucson's congestion problems. Nassi guesses it may improve things 10 to 15 percent in total, but stresses it is also advantageous because it doesn't cost much to implement, unlike road widenings or other construction projects.
But, he warns, "We can't design our way out of all congestion. Technology won't be there to save us. There will always be some delays. Technology makes what we have work to the best of its capability, but during peak hours it won't satisfy everyone."
