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2. IMPLEMENTATION RESULTS

2.1 PRE-FOT INCIDENT RESPONSE

Prior to the FOT, the primary emergency response agency for Washington State roadways was the Washington State Patrol (WSP). Emergency cellular 911 calls were received at the WSP dispatch center and in-field troopers regularly report progress to the dispatch center as they respond to crashes and events in the field. As a result, the WSP dispatch center was the primary source of information about incidents impacting the Washington State roadway system.

Also prior to the FOT, WSDOT TMC operations have been shown to be a valuable resource in responding to events because of the traffic surveillance capabilities used to monitor incident sites and identify travel routes to those sites. WSDOT has also provided personnel and equipment to help manage traffic at event locations and clear incidents to restore normal traffic flow.

Because of these complementary capabilities in responding to incidents, WSP and WSDOT have cultivated a long-standing history of working together to improve incident response. At an organizational level, the two agencies have held annual senior management retreats and monthly regional coordination meetings. One result of this coordination was the establishment of a Joint Operations Policy Statement (JOPS) that states the two agencies would share data to improve incident response. This policy was implemented by encouraging WSP CAD dispatchers and WSDOT TMC operators to exchange information about events and by providing access to each organizations incident response data.

Prior to the implementation of the FOT, the following process was used to exchange incident information between the two agencies. WSP dispatchers, usually the first notified about an event, would initiate the exchange of event information. While the WSP dispatchers' primary responsibility is to manage the WSP's response to an incident, the dispatchers also notified WSDOT TMC operators about significant incidents verbally by radio or telephone. Alternately, TMC operators might note information about an incident by monitoring information on the WSP CAD remote data terminals located in WSDOT TMCs. These terminals provided read-only access to current activities being logged into the WSP CAD.

In addition to the incident information data exchange process described in the preceding paragraph, it should be mentioned that the WSP Dispatch and PSAP Supervisor in the Bellevue region of the State (northwest) also had access to and secondary control of CCTV cameras in the metro area. This access is also used to identify and provide information about incidents.

WSDOT TMC operators used this incident information to help manage their response to each incident. Responses might have included dispatching road crews to manage traffic at the incident and entering information into WSDOT's CARS platform. WSDOT dispatchers used CARS to assist in roadway response, and CARS supplied a portion of the traveler information content to WSDOT's 511 system and Internet pages. CARS is used to provide communication and coordination support.

Throughout an incident, WSP dispatchers and TMC operators continued to use these communication systems?radio, telephone, and data terminals?to share information and coordinate responses. Although this system has proven effective in facilitating the exchange of information, it also was determined to be a time- and resource-intensive approach to communication. One result of using this system was that it sometimes limited the amount of information communicated between the agencies about a particular event.

In an attempt to address this situation and ensure that event information exchange captured all reported events, WSP and WSDOT agreed to participate in the FOT to facilitate the development of an integrated CAD-TMC system. The timing of the FOT also coincided with the implementation of a new, state-of-the-art WSP CAD system. The new WSP CAD system established a common platform used by all WSP dispatchers and also improved WSP's ability to record incident data.

2.2 THE WASHINGTON CAD-TMC FOT

The Washington State deployment of an integrated CAD-TMC system included the following primary elements:

Component #1 - PRIMARYALERT

PRIMARY ALERT served as the main connection between the WSP CAD system and the WSDOT TMC. This component filtered the CAD data and transferred those portions suited for receipt and used by the TMC. The key aspects of PRIMARY ALERT are as follows:

Component #2 - RESPONSE SUPPORT

The intent of the RESPONSE SUPPORT component was to transfer any available information from WSDOT to the WSP that would support WSP response efforts. Unlike PRIMARY ALERT, this information transfer consisted of information about other external events near the incident. For example, when a crash was reported to WSP on I-5 just north of Tacoma, the PRIMARY ALERT component was intended to transfer information from WSP to WSDOT.

RESPONSE SUPPORT displayed information to WSP about nearby events, such as slow traffic, construction, accidents, or other extreme events (i.e., pass closures, flooding, National Weather Service warnings, etc.) that might impede a patrol officer's response.

Component #3 - SECONDARY ALERT

The third component, SECONDARY ALERT, was intended to reach those event responders beyond the WSP and WSDOT jurisdictions, including local EMS providers, tow truck dispatchers, and local utility companies. The general philosophy regarding SECONDARY ALERT was described as:

To provide as comprehensive and complete information in the most useful fashion to secondary responders across the entire State of Washington, recognizing that the dispatch systems of these secondary responders vary widely in complexity.8

At least one EMS provider (Skagit County EMS) was going to serve as a demonstration for the transfer of information to the CAD system of a non-WSP responder. However, for a variety of reasons discussed in section 2.3, Skagit County EMS did not participate in the FOT. The SECONDARY ALERT component was not included in the FOT.

The first two components identified above were based on the following principles:

The vocabulary used for the exchange of incident management and traffic management information was based on industry-approved standards for data elements and messaging, specifically, Message Sets for External Traffic Management Center to Center (MSETMC2C) and the Institute of Electrical and Electronics Engineers (IEEE) 1512 standards:

The proposed system architecture for the Washington State CAD-TMC FOT integration is shown in figure 1. The two-headed arrows originating from the World Wide Web signify its use as an interface for sharing information between the WSP CAD, Skagit Count EMS CAD, other CAD systems, and the WSDOT TMC CARS database.

Diagram of Washington CAD-TMC System Architecture.D
Figure 1. Washington CAD-TMC System Architecture.

2.3 SYSTEM IMPLEMENTATION

The Washington State CAD-TMC integrated system was developed much as was intended and described above. There are several aspects of the implementation that are important to note, as described in sections 2.3.1 through 2.3.3.

2.3.1. Secondary Response Agency

Skagit County EMS was initially identified to participate in the FOT as a secondary response agency. However, this agency was not included in the implemented system. As a primarily rural county in Northwest Washington with one small urban area, Mount Vernon? Burlington, it was determined that it would be difficult to identify sufficient value for Skagit County EMS to participate.

Skagit County EMS handled all emergency response dispatch, except for WSP, in Skagit County. The original concept was that by informing Skagit County EMS about when, where, and how WSDOT and WSP were responding to traffic incidents, the Skagit County EMS dispatchers would be able to better route their emergency response units. As the project and discussions between WSDOT and Skagit County EMS progressed, this concept did not appear to really be a benefit. Skagit County EMS was too small, with too focused a mission to really be a good candidate as a secondary responder incorporated in the integrated system.

2.3.2. System Modification

The approach taken by WSDOT required some modification to the WSP CAD software. These modifications were needed to allow the WSP CAD system to export information from WSP CAD records to the WSDOT. The WSP and its CAD vendor modified the system to send this information every 2 minutes. It turns out that the latency built into this decision created issues with WSDOT operators in the major urban areas of Seattle and Tacoma. More discussion of this issue is included below and in subsequent sections of this document.

Originally, WSDOT was going to be able to populate event information in the WSP CAD system through a "hazard flag." The idea was to have the WSP system show WSDOT actions and activities, which were defined as traffic conditions, event information, and construction and maintenance activities. However, the CAD application was primarily historical and tended to be fed by information internal to the CAD system. Having WSDOT systems feed the WSP CAD system did not turn out to be feasible in the manner originally intended. Instead, WSP could access WSDOT event information through a Web interface and congestion information through either a Web interface or TMC workstation software. The problem with this approach was that dispatchers needed to change their normal work processes to see this information. The dispatchers typically looked only at the WSP workstation screen.

As a follow-on consideration to the FOT, WSDOT is now contemplating sending a map layer to the WSP dispatch terminals that could show events and perhaps traffic congestion. Also, WSP anticipates that vehicles will be equipped with AVL devices. WSP also has suggested that the WSDOT incident response vehicles and service patrols become equipped with AVL as well so as to display their locations in the WSP system. Together, these approaches will provide the functionality originally envisioned by WSDOT.

There also were changes made in the WSDOT CARS event reporting software. The WSP CAD system sent information every 2 minutes to a WSDOT translation program that converted the CAD data into standard IEEE 1512 messages and codes. The CARS system was modified to accept IEEE 1512 messages from external sources. The system was designed so that if the WSP CAD system is updated to send messages in IEEE 1512 format, the translation program can be removed to enable the CAD system to communicate directly with CARS.

In the WSDOT CARS, the event reporting configuration utilized periodic updates, originally on the order of once every 5 minutes. Combining the 2-minute cycle of the WSP system and the 5-minute update cycle within CARS presented some reporting latency problems for the WSDOT operators in the Seattle and Tacoma urban areas. The operators wanted the incident information and updates to go to the public via 511 and the WSDOT Web site as quickly as possible. With as much traffic and as many incidents occurring in the urban areas, coupled with shorter travel times than in rural areas, operators indicated that quick reporting was critical in providing efficient and timely emergency response.

WSDOT improved its servers and made other improvements to reduce the latency to an average of 4 minutes from the time the CAD system reported the incident to the time the incident was displayed on 511 or the Web site. Additional improvements could be made if the WSP output was already in IEEE 1512 format so the translation program could be deleted from the procedural loop. However, it is likely that some level of concern will continue as long as the WSP CAD system only exports information every 2 minutes.

2.3.3. Use of Standards and Data Translations

The modification to the WSDOT CARS system enabled the use of IEEE 1512 messages. The CARS reporting system also used the Traffic Management Data Dictionary (TMDD), Society of Automotive Engineers (SAE), Advanced Traveler Information System (ATIS), and geo-location referencing standards. The use of these standards in this system was a system requirement from the beginning. Using these standards will allow additional systems to provide input to the CARS system seamlessly, as long as the other platforms also conform to standards.

The use of geo-location referencing standards is worth mentioning. The WSP CAD system, like many State police systems across the nation, used State Plane Coordinates for location referencing. CARS used latitude-longitude. The CARS was modified to translate State Plane Coordinates to latitude-longitude. This enabled a relatively straightforward translation as long as the geographic area of interest is not too large. However, as the area increases, errors in the projection of locations on the globe to a plane get larger. These errors get larger with distance from the center of the projection. The translation, therefore, is not uniform. Making the translation from State Plane Coordinates to latitude-longitude took longer to make accurate than was originally envisioned.



7 Neither of the secondary interfaces was deployed during the FOT. More information on this fact is documented in section 4, Test Results.

8 Adapted from: Legg, Bill, WSDOT, "Application for RFA Number DTFH61-02-X-00062, Computer-Aided Dispatch - Traffic Management Center Integration Field Operational Test."

9 Source: Incorporated from: Legg, Bill, WSDOT, "APPLICATION FOR RFA Number DTFH61-02-X-00062, Computer-Aided Dispatch- Traffic Management Center Integration Field Operational Test," p. 16.

10 It is important to consider the impact on dispatchers' work processes for any agency planning to implement an integrated CAD-TMC system. This situation is discussed more in detail in the lessons learned portion in section 6 of this document.

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