Congestion has many potential causes and improving mobility helps mitigate the problem. Reducing congestion means reduced delay, more predictable and lower trip times, lower travel costs and reduced emissions.
The first option to be considered is to make better use of existing infrastructure as they are usually most cost-effective, are flexible in being tailored to each particular situation, can be implemented rapidly and provide publicly visible changes.
Quick clearance of traffic incidents has the potential for considerable reductions in congestion. Attention to traffic flows at road works sites is also important.
Improving the operation of traffic control systems, such as improving traffic signal cycle times by being adaptive in real-time to traffic demand and coordinating signals to smooth key traffic flows, including ramp metering traffic joining a motorway.
Small infrastructure adjustments may be required to address bottlenecks at intersections or for turning and merging movements. Use of the shoulder as an extra lane in peak periods is another innovation being used.
Use of technology such as electronic toll collection, variable speed limits, lane controls and providing traveller information through roadside variable message signs also assist in reducing congestion. Potentially the use of communication between vehicles and vehicle to roadside will enable onboard traveller advisories on traffic conditions, etc and further improve traffic flows.
Providing more trip options for how and when a trip is made is a useful means of mobility improvement, and congestion reduction. This could mean time-shifting travel to a different time (broadening the peak period), travel by an alternative means, such as sharing a ride or using public transit (more ‘efficient’ travel), or not travelling at all for some trips (eg telecommuting). These all compete with the flexibility, comfort and ease of use of the car.
This may require adding capacity in the form of more public transit capacity, including more buses, trains and infrastructure, such as dedicated high occupancy vehicle lanes, bus transit lanes, freight rail and cycle facilities.
Planning new developments can also assist by encouraging more ‘efficient’ travel, such as by locating on a quality transit route and reducing the use of cars by restricting parking and encouraging walking and cycling.