3.5 Maintaining Road Serviceability and Safety
Maintaining road serviceability covers, in the event of a disturbance, all field operations designed to maintain or restore conditions of road use that are as close as possible to the normal situation. In order to maintain or improve road serviceability and safety, pro-active and re-active measures can be applied. Pro-active measures focus on the quick detection and verification of incidents and unsafe road conditions, fast response and clearance, and implementing pre-prepared strategies to restore normal operations. Traveller information is also an important preventive measure. Timely warning of unsafe road conditions and congestion reduces the occurrence of crashes and unnecessary delays.
Incident management strategies have been found to reduce freeway congestion by up to 30%, secondary crashes by 80%, travel times by 20% and incident duration by 50% (World Road Association 2003). The early detection of incidents and impassable/unsafe road conditions and rapid response and clearance thereof will improve road serviceability and safety and thereby decrease congestion.
Maintenance, rehabilitation and upgrading works, as well as planned special events, must also be regarded as incidents that will have a major effect on traffic conditions if not planned properly. Major weather events can also adversely affect traffic conditions, so technology to detect and track these events, and strategies to respond to them, are also important.
Table 3.8 provides a synopsis of objectives, tools, equipment and outcomes for maintaining road serviceability and safety, and lists some considerations. Key elements are discussed in more detail in the ensuing sections.
|Maintenance, rehabilitation, upgrading works notification(1)||To maintain, restore or improve road conditions to better accommodate traffic.||Standard construction plant and equipment, manual labour.||Planning and scheduling tools.|
Better trip choices arising from notification.
Requires careful planning:
|Road condition warning||To warn the user about road conditions such as icy roads and incidents.||CCTV, inductive loops and other sensors, variable message signs, communications networks.||Information processing.|
Better trip choices.
Theft of equipment can be a major problem.
|Control centre||To observe and respond to various incidents and events.||Various||Various|
Better trip choices.
|Effective but requires coordination between parties.|
- This is not a traffic management issue per se, but is included here for completeness in the context of road network operations as opposed to traffic operations.
Source: Adapted from World Road Association (2003).