In April 2000, the Federal Highway Administration produced a cross-cutting study to examine successful incident management practices in a number of communities across the United States. The document, Incident Management Successful Practices – A Cross-Cutting Study, focuses on managing typical traffic incidents averaging less than two hours in duration. The study emphasizes having an incident management plan and executing it with full cooperation among all of the organizations involved. Included in the study are the lessons learned from the experience of many transportation agencies that have well defined incident management programs.
The faster an incident is detected and verified, the quicker the appropriate response teams can be dispatched to and deployed on the scene. Detecting incidents quickly and accurately leads to reduced traffic disruptions and large time savings. When an incident management plan is developed, consideration should be given to the resources allocated to improving incident detection and verification times.
Based on the experience of transportation communities nationwide, the following suggestions are offered for identifying detection and verification resources:
- Provide a combination of detection methods to effectively detect incidents rapidly. The use of cellular phones over the past few years has become a ubiquitous method for detecting and reporting incidents. Detection times can occur in as little as one minute in most metropolitan areas. However, the accuracy of the information provided by motorists calling in an incident is often not sufficient enough to initiate an early response. It also may not be wise to rely on cellular phones when traffic volumes are low or in isolated areas. Transportation management professionals rely on several methods of detecting incidents including vehicle probes, call boxes, automated incident detection, CCTV cameras, and safety service patrols to reduce the time it takes to detect and verify an incident. Having a mix of detection methods enables a more accurate response in a timely manner. As an example, at the Advanced Transportation Management Center in Austin, Texas, in addition to incidents reported from cellular phones, transportation management professionals rely on several methods of incident detection and verification: a loop detector system that monitors traffic thresholds and notifies the operators of a potential incident; calls from service patrols and police; and on some occasions, operators monitoring the CCTV system.(1)
- Provide training to dispatchers to elicit useful information about the incident from motorists. As incidents are detected more and more by motorists calling from the incident scene via cellular phones, it is becoming the primary way incidents are reported and detected. It is not uncommon for a call taker to receive many phone calls for the same incident. But the accuracy of the information is often insufficient to initiate an early response. It is difficult to get all of the physical details from a single passing motorist to fully verify an incident. Dispatchers can be trained to obtain more information about an incident from subsequent callers. This technique encourages callers to continue making voluntary calls to report incidents and improves the likelihood that the phone calls can also serve as a reliable verification tool.
- Provide and promote toll-free cellular phone numbers to report incidents.
- Provide a centralized system for gathering and disseminating incident detection information.
- Place CCTV cameras strategically at high-incident locations when funding is limited.
- Use compressed video as a cost effective alternative to full motion video for incident verification.
This lesson suggests that there are several ways that incidents can be detected, the quickest among them is cellular phone use by passing motorists. Experience has shown that though this may be the quickest, it is not necessarily the most accurate. Having other detection methods (e.g., loops, probes, and call boxes) increases the possibility that the incident will be detected quickly and accurately. Having dispatchers trained in how to obtain the correct information is also important. For verification, some regions provide full coverage of CCTV cameras while others provide spot location coverage based on high incident data. All of these methods for detecting and verifying incidents have a significant impact on the performance of the facility and contribute to a successful incident management program promoting safety, efficiency, mobility, and customer satisfaction.
(1) Source: NCHRP Report 520 Sharing Information between Public Safety and Transportation Agencies for Traffic Incident Management