WHAT IS SMART TRAFFIC MANAGEMENT
Traffic congestion is a major problem in most cities due to increased population and vehicle usage resulting in roads quickly becoming incapable of managing the traffic. Advanced traffic management systems, or SMART traffic management systems, are now being developed to ameliorate the safety and efficiency of transportation infrastructure.
Traffic congestion changes due to peak/off-peak volumes and is a recurrent concept drift whereas an accident or breakdown is a non-recurrent concept drift. Special importance is placed into identifying non-recurrent concept drifts as it could affect the entire road network. Therefore, SMART traffic management systems collect and analyse data. This in turn can be relayed back to the motorist as information on Variable Message Signs(VMS). An example of this is the new system recently introduced on the M50 between Palmerstown and Finglas junctions. When a breakdown or accident occurs, traffic controllers have the ability to advise motorists of the appropriate safe speed to travel and to inform them of which lanes are blocked ahead, diverting them into alternative lanes as necessary. The ‘Smart Traffic Management Platform’ (STMP) is an expansive intelligent traffic data integration and analysis platform, which integrates heterogeneous traffic data sources. The purpose of this type of system is to predict such non-recurrent events and bottlenecks and put in place control measures to counteract them.
Another example of a similar SMART traffic management system can be found in the UK where the hard shoulder can sometimes be used to accommodate vehicles in peak traffic flows. The use of the hard shoulder lanes is governed by arrows on VMS above each lane combined with advisory speed limits. There are some safety concerns over this system as the hard shoulder is designed for emergency use and breakdowns only and when that refuge is taken away and the lane fully opened to all vehicles, vehicles that breakdown are stranded in ‘live’ lanes of traffic.
In temporary roadworks there are also Intelligent Traffic Management Systems (ITS) integrated into temporary traffic signals that allows the TM Designer to control junctions with systems that closely match the permanent system already in place. Temporary traffic signals can operate under several different modes:
- Vehicle Actuated
- Remote Control
A manual system relies on a traffic operator standing at the side of a signal and controlling the phases by switching them on a control panel. Vehicle actuated is where there is a sensor in the traffic signal that picks up approaching vehicles and switches between phases in accordance with the demand. Signals can also be pre-programmed with settings for red and green times of the signal phases depending on estimated traffic flow. Finally, remote control is where a traffic operator is located in a safe position and can switch between phases with the use of a handheld remote controller.