Congestion is a major economic, social and environmental issue in most large urban centres around the world. The inability to build sufficient new infrastructure to meet the demand results in recurring congestion. But significant congestion also occurs from temporary reductions in capacity, with an increasing number of major traffic incidents occurring in the high traffic flows, such as vehicle breakdowns, spilled loads and crashes.
Major traffic incidents result in significant traffic impacts, closure of traffic lanes and virtual gridlock for extended periods. Of particular concern are incidents on high traffic routes at critical times and locations.
Truck crashes block major roads for several hours, while the trucks and their cargo are carefully salvaged to avoid further damage, often after long delays waiting for the right equipment to come to the site or waiting for an owner or insurance company to make the necessary arrangements.
Major crashes result in roads being closed for long periods while people are rescued and transported to medical facilities and the necessary investigations and evidence gathering are carried out.
These incidents result in extensive congestion, delays, missed deadlines for flights, deliveries or business appointments, costs to business, secondary crashes, and expose responders to traffic safety hazards.
Traffic incidents are a major contributor to traffic congestion and impose considerable cost to the community. A combination of studies and analytical work by the US Federal Highways Administration estimated that roughly 25% of the congestion delay experienced in the US is due to traffic incidents. A study in the United Kingdom by the Highways Agency found that incidents account for about 25% of congestion on the major roads.
How can we reduce the congestion impact of traffic incidents?
As part of a systematic approach to traffic incident response and management, rapid and quick clearance has the potential to result in major reductions in the duration of closures and blockages and the resulting congestion.
However, a major challenge to improving incident response is the fact that there are many different agencies and organisations involved in responding to incidents, each with their own priority and agenda, which makes it difficult to coordinate and focus incident clearance efforts.
Many jurisdictions (usually at a state or regional governmental level) have adopted a quick clearance or open road policy as a result, and also enacted supporting legislation.
For example in Florida an Open Roads Policy, an agreement between the Highway Patrol and the Department of Transportation, has a stated goal to clear traffic crash scenes and reopen roads within 90 minutes. The policy states that roads will not be restricted or closed any longer than is absolutely necessary and that vehicles and debris will be removed as quickly as possible.
Roadways will be cleared of damaged vehicles, spilled cargo and debris as soon as it is practical and safe to do so. Due to the urgency of removing vehicles in a timely manner, damage could occur to the vehicles or cargo as a result of clearing the roadway. While reasonable attempts to avoid such damage shall be taken, the highest priority is maintaining safety and restoring traffic to normal conditions.
Supporting quick clearance legislation authorises the removal of disabled or wrecked vehicles from travel lanes. ‘Hold harmless’ laws furnish immunity to incident responders from civil liability in connection with removing vehicles and spilled cargo involved in a traffic incident and obstructing adjacent traffic flow.
Fatal crashes also result in major delays, as detailed investigations are needed and Police have to balance the need for evidence and reporting requirements against traffic delays and the threat of secondary incidents.
High level (political and top management), aggressive quick clearance polices, similar to the ‘open roads’ policies referred to above, can greatly assist in reducing the duration of major incidents.
Strong partnerships and agreed inter-agency operating procedures for key responders are needed to complement the policy. Quick clearance laws and regulations provide the underpinning legal basis. Providing key infrastructure and services, such as incident response units, traffic officers, and heavy vehicle towing equipment on standby, complete the package of initiatives needed.