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21st Century Operations Using 21st Century Technologies
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Process for Establishing, Implementing, and Institutionalizing a Traffic Incident Management Performance Measurement Program

STEP 2: Determine What Data are Available

When determining what data are available, consider the most common sources for traffic incident management (TIM) data. Data in support of TIM performance measures generally fall into four broad categories:

  • Transportation data.
  • Law enforcement data.
  • Combination of transportation and law enforcement data.
  • Other data sources.

Each of these categories is discussed below, along with the advantages and disadvantages associated with each data source.

Two fireman look at a crashed car on it's side. (Photo Source: Cambridge Systematics, Inc.)

Transportation Data

In this case, a transportation agency, usually the State department of transportation (DOT) or a regional metropolitan planning organization (MPO), has the lead role in collecting/reporting TIM performance. The data flow typically begins when the transportation agency becomes aware of an incident through its network of intelligent transportation systems (ITS) devices or via a call and begins tracking and monitoring the incident. The traffic management/operations center (TMC/TOC) will typically use either advanced transportation management systems (ATMS) software or another electronic incident tracking system to log the incident data. In some cases, the transportation agency will supplement the information gathered by TMC/TOC operators with information provided by transportation personnel in the field, such as freeway service patrol (FSP), via radio communications (and at which point the information is logged into the system by a TMC operator) or via mobile data entry.

Advantages

Global view of crash/incident

When incidents occur within view of a closed-circuit television (CCTV) camera, TMC/TOC operators have a bird's-eye vantage point of the activities associated with the incident (e.g., times lanes closed/opened, number of vehicles involved, type of responders and times on/off scene, secondary crashes). In addition, as TMCs/TOCs are hubs for traffic management, they are generally informed by various sources, including field personnel, law enforcement, and the media.

Focused attention on crashes/incidents within coverage area

TMCs/TOCs are able to capture almost every crash/incident within their coverage area during their hours of operation.

Logging/tracking tool

The operator's interface and ATMS software provide a mechanism for directly entering incident information into a database system.

Data ownership

The DOT is generally the agency responsible for reporting on TIM performance; therefore, it makes sense that the DOT is the "owner" of the data and has full understanding as to how the data are collected.

Disadvantages

Limited coverage area/times result in missed crashes/incidents

Incidents and crashes that occur beyond the ITS coverage area, or outside of TMC/TOC operational hours, are generally missed unless the TMC/TOC is notified of these incidents by other sources. In these cases, some DOTs noted that they are only notified of major incidents, such as fatalities and full road closures. One DOT noted that it is not contacted if the incident can be "handled" in under 30 minutes. In some cases, if the DOT does not manage an incident, the information does not get entered into their system. The result is incidents/crashes in which there is no information on TIM performance.

Law Enforcement Data

In this case, a law enforcement agency, usually the State police or highway patrol, has the lead role in collecting TIM performance data. Incident data are collected by law enforcement officers at incident scenes using the statewide crash report, electronic crash reporting system, and/or computer-aided dispatch (CAD) system. The law enforcement agency may have ownership of the data and may be responsible for the reporting, or it may send the data to the State transportation agency for analysis/reporting.

Advantages

Increased coverage of crashes and incidents

There is almost always a law enforcement officer present at crash/incident scenes, which allows for more ubiquitous coverage of incidents (not limited to TMC/TOC coverage area and times).

Law enforcement officers already collect information at crash/incident scenes

Law enforcement officers complete crash/incident reports, a process that allows for a direct and standard mechanism for gathering data needed for TIM performance.

Disadvantages

Not necessarily focused on data/information collection

While completing forms is part of a law enforcement officer's duties at a crash/incident scene, officers have other duties to perform, such as maintaining the safety of first responders and victims, accident investigation, and coordination with other first responders. These activities could limit the amount/timeliness/accuracy of the information collected.

Data ownership

The law enforcement agency may not have (or want) ownership of the data and would need to determine how to migrate the data to the DOT for analysis and reporting.

Combination of Transportation and Law Enforcement Data

In this case, a transportation agency, usually the State DOT, has the lead role in collecting/reporting TIM performance measures; however, the information being collected by the DOT is supplemented through integration with one or more law enforcement CAD systems. This integration is generally achieved through a direct feed from the CAD system into the TMC/TOC, at which point the information is either manually input into the system by TMC/TOC operators or the data are automatically entered into the system. This model will likely be the most successful in areas with pre-established TIM groups or coalitions that are already working cooperatively to improve incident management in their area.

Advantages

Robust database

This approach may offer the best of both worlds in terms of the quantity and quality of data, combining both sources into one.

Shared understanding of the importance of traffic incident management performance

This approach usually involves a memorandum of understanding (MOU) between transportation and law enforcement regarding the shared use of data, which can start the conversation about TIM performance, getting agencies on the same page with respect to the importance of quick and safe incident clearance.

Disadvantages

Potential institutional challenges/barriers

Institutional silos may be an impediment to reaching agreements about what data are to be shared.

Potential technology challenges/barriers

Integrating diverse technology systems can be a complicated and expensive endeavor that some agencies may not be willing or able to undertake.

Other Data Sources

Beyond transportation and law enforcement data, it is worth exploring what data are available through other sources that could be used to support TIM performance measurement. Sources to consider include:

Fire and Emergency Medical Services Computer-Aided Dispatch Systems

Information from fire/Emergency Medical Services (EMS) CAD systems could be used to supplement the information available from transportation and/or law enforcement. This information might include the arrival and departure times of fire/EMS responders, the number of fire/EMS responders and response vehicles at the scene, and the number and type of injuries.

Towing Services

Towing companies are yet another type of responder that may record incident information, such as arrival and departure times, clearance time (when they are the only responder), and other potential useful incident-related information.

511 Systems

Incident information put into 511 systems (by law enforcement, media, etc.) is another potential source of data for measuring/assessing TIM performance. Tennessee Department of Transportation (TDOT) currently is developing a new centralized ATMS that will integrate the current statewide incident database with the 511 system. TDOT captures most of the incidents in the urban areas within its coverage areas; however, it currently has very little knowledge and information of incidents outside of these areas. As the Tennessee Highway Patrol (THP) enters all incidents over 30 minutes into 511, the integration of the ATMS with the 511 system will allow TDOT to capture data on additional incidents.

Public-Safety Answering Points

A Public-Safety Answering Point (PSAP) is a call center responsible for answering calls to an emergency telephone number (e.g., 911) and for dispatching emergency services. A county or large city usually handles this responsibility, and the information entered into the PSAP system can provide information on incidents not captured by the State DOT or law enforcement agency, as well as supplemental information on incidents managed by the State.

Social Media/Crowd-Sourcing Apps

Social media and crowd-sourcing applications are a new way of getting incident information. Both the Virginia Department of Transportation (VDOT) and the Florida Department of Transportation (FDOT) are exploring the use of WAZE as a source of incident information. WAZE is a community-based traffic and navigation application that encourages users to input information about the activities happening along their routes. This information can help to identify incidents outside of TMC/TOC coverage areas, as well as provide information on incident details and impacts (delays, queue lengths). FDOT notes that, while the TMCs are quicker to identify incidents within their coverage areas than via WAZE, the use of WAZE has allowed them to more quickly identify incidents outside of their coverage areas than they would without the data.

Virginia Department of Transportation—Public-Safety Answering Points Integration

VDOT has put a concerted effort into integrating PSAP information into its process of capturing incident information and data. While VDOT's focus is reporting TIM performance on interstate highways, VDOT has conducted more than 15 local/regional PSAP integrations across the State and is working to add more. With the addition of this information, VDOT is able to capture data for about one-quarter of the incidents on primary and arterial routes statewide, which has increased its awareness and knowledge of TIM performance outside of its primary TOC coverage areas. VDOT's approach has been not to impact the operations of the PSAP or to improve the system; instead, VDOT takes what it can get and find ways to use it. Filtering components on both ends of the connection remove personal information and ensure that only relevant traffic information gets shared. The information is very granular and varies from one PSAP to another. As much of the information is in free-form text, VDOT relies on the TOC operators to comb through the information and use their knowledge to extract what is relevant. As a result, VDOT ultimately manages about one-quarter of the incidents from the PSAPs.

Checklist of Data Elements

As part of National Cooperative Highway Research Program (NCHRP) 07-20, a common database schema and data dictionary were developed to help guide agencies in collecting the required and desired data elements for consistent reporting of TIM performance. These documents are available for view and download on the TIM PM Web site at http://nchrptimpm.timnetwork.org/.

To assist agencies in determining what data elements are available to them and from what sources, a comprehensive Checklist of Data Elements by data source is provided in the appendix of this document. This checklist is consistent with the NCHRP 07-20 database schema and data dictionary.