Traffic Congestion

The bad news is that at least 75% of all traffic lights in the United States are either outdated or poorly timed. The good news is that technology is currently available that allows us to adjust traffic light timing in real time to adapt to changing conditions. This is accomplished by using signal vehicle detection hardware such as “adaptive signaling” and “traffic responsive signaling” to count cars as they approach an intersection. Upgrading all of our 330,000 traffic signals would cost an estimated $9.9 billion. However, when you consider that in 2011 alone, we wasted $121 billion in time and fuel sitting at traffic lights there is actually a 12 to 1 savings ratio. Consider the following facts:

· We wasted 5.5 billion hours sitting at traffic lights. Keep in mind that nearly 76 percent of vehicle-miles driven are on urban streets.

· Texas A&M Transportation Institute found that in 2011 Americans wasted an average of $818 each, sitting in traffic.

· The total amount of additional carbon dioxide that was released into the atmosphere was 56 billion pounds or the equivalent of 380 pounds per commuter.

· Total fuel consumption was increased by 10% or 17 billion gallons of motor fuels per year.

· According to the U.S. Department of Transportation, poor signal timing accounts for up to 10 percent of all traffic delays or 295.8 million vehicle-hours of delay on major roadways alone.

· The 2012 National Traffic Signal Report Card gives a grade of 69 or D+ to the overall management of traffic signals in the U.S.

· A project in Syracuse, New York, found signal optimization cut travel time 34 percent, reduced vehicle stops 16 percent and lowered fuel consumption 13 percent.

The following is from an article by: Matthew Scholz, Puget Sound Business Journal, June 6, 2008:

· There are more than 330,000 traffic signals in the U.S. in dozens of complicated intersecting jurisdictions that all bid for systems independently, and most of the systems don’t communicate with each other.

· California’s fuel-efficient traffic management system had a benefit-to-cost ratio of 17:1 between 1983 and 1993, when metrics such as the reduction in fuel consumption, total trip time, and congestion are taken into account.

· In Texas, a similar system boasted a 62:1 ratio in 1992, and technology has come a long way since then.

· A major problem is that most transportation agencies don’t really care how long it takes for individuals to get to work or how much fuel they waste getting there.

· Companies with private fleets of vehicles are rapidly deploying software that helps save hundreds of dollars in fuel per vehicle each month by optimizing the order of the stops the vehicle makes and highlighting unnecessary ones.

· Many systems currently deployed already support traffic responsive signaling, but the jurisdiction in charge often hasn’t turned it on due to lack of funds for technicians and traffic managers to run it.

· Billions of dollars are allocated to capital expenditures, but it is hard getting millions for operations and maintenance. For every dollar we spend on roads we only spend a penny on ITS, and many jurisdictions spend essentially nothing on maintenance tasks such as updating traffic signal timing.

· Today it is still very difficult for transportation authorities to get money for operations and maintenance because most money they get is earmarked for capital expenditures such as new roads.

· The labor-intensive process of collecting sample data to create coordinated timing plans is imprecise and limited in its effectiveness. In many cases, upwards of 5–7 years (or more) of signal coordination is based on one 6–10 hour sample of traffic.

· Even the best, most up-to-date plans cannot respond to random fluctuations in traffic such as before and after special events.

· The latest traffic controllers use digital hardware, but at their core they are constrained by analog concepts such as fixed offsets, common cycle lengths and standardized allotment of green time, or splits.

· By emulating old-fashioned thinking, these controllers are unable to quickly serve the phases or movements that best accommodate actual demand. The technology is simply not sophisticated enough to move traffic as efficiently as possible.

Traffic signal technology is the most cost effective way to maximize traffic flow and help mitigate congestion. Therefore, I suggest a federally funded program to transform our nation’s traffic signals using 21st century technology.

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