As someone who lives in Sydney, with 4 million people, hundreds of thousands of cars and not too many freeways compared to our american friends, having the chance to drive in Arizona allowed me to make some observations about how good our SCATS Urban Traffic Control (UTC) System is.
Firstly, it is evident that they have a lot more infrastructure that carries a lot of road traffic in and around urban areas along with vehicles that are not seen much in the rest of the world the so-called “trucks” and “SUVs”.
I had the opportunity to experience driving in urban areas and noted how much time was “wasted” waiting for pedestrians that weren’t there to cross. Why I asked? Because, not having the capability to let a pedestrian “notify” a Traffic Signal Controller that a person(s) is waiting to cross means “introducing” a pedestrian crossing phase whether someone is there or not.
This is something that hasn’t been seen in Australian intersection for many years.
In addition, the same concept applies to cars for example on a small side street waiting to get on a major arterial road, but failing to be able to “notify” its presence to the Traffic Signal Controller by means such as an inductive loop in the road surface or a video camera detector.
Again, the poor motorist on the side street has to wait until his “turn” comes up to cross the road. More wasted time.
This also impacts the motorist on the major arterial road who has had to stop because instead of switching the green phase on the major arterial as soon as there are no more side street vehicles, the major arterial road user has to wait the whole time allocated to the side street.
More wasted time.
Clearly, fixed plan time systems are inefficient and therefore will accumulate traffic in quasi peak times all the way through peak times.
It is then that one can see the efficiency of using an adaptive urban traffic control system such as SCATS to trim the wasted time at intersections I have just described and allow road users to keep moving as much as possible – getting rid of a bank up of road traffic.
Every cycle of a fixed time plan means building in fixed delay throughout the day.
There is a growing awareness that systems such as SCATS ensure that signalised road intersections run as efficiently as possible whilst trying to provide coordination in the direction of most traffic during peak periods.
It is the efficiency and shortness of each cycle that ultimately directs the most green on time to the direction that has the most traffic and leads to reduction in fuel consumption and shorter trip times.
These are things most people in Australia and New Zealand have been used to and benefited from the most.
It will be interesting to see if the roll out of systems such as SCATS can bring marked improvements in travel time even in America.
