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The potential benefits of private sector traffic data, and · Manual entry into a statewide or regional condition/
that mobile probes are used to gather the data, offers tremen- event reporting system; or
dous opportunities for much wider spread data coverage than · Automated system to system data exchange.
what is possible with the current infrastructure of sensors. In
addition, many public agencies are challenged by the costs The following sections provide a synthesis of the findings
of maintaining and repairing intrusive and nonintrusive traf- related to these two categories.
fic detectors, and private traffic data collection could supply
this data, if accuracy is proven to be adequate. Manual Event and Incident Entry
In summary, for reasons of reducing traffic data collection Manual entry is often performed by selecting predesignated
costs and increasing geographic coverage of traffic reports, phrases and location points to ensure standardized descrip-
many public agencies are either testing or using private sec- tions of events. The entry of event and incident descriptions
tor traffic data. Examples were cited of tests of services from is often performed in a traffic management center or by
Inrix and AirSage; however, additional companies and ven- operators statewide using a distributed network of system
tures may also develop and offer traffic data. interfaces. Accuracy and timeliness are challenges with
manual entry of events. During peak periods, operations
staff are busy and are challenged to find time to enter even
Event And Incident Data Availability quick entry of event and incident reports.
Descriptions of current and planned event and incident One pressing challenge to event and incident entry is
data describes such things as road construction or mainte- gathering the knowledge about the event or incident. For
nance activities, crashes or other incidents, road or lane clo- example, road construction and maintenance activities are
sures, and special events (e.g., parades, running/bicycling an information source that is difficult to maintain accuracy.
events) that will affect travel and parking. These events may Often, road construction activities last for long durations and
describe either currently active situations or planned events general messages such as "intermittent lane closures from
for future dates and times. These descriptions are critical to June to August" are common. Travelers want details about
complement current traffic reports and to give travelers an daily activities, and condition reporting systems allow the
understanding of the cause and expected duration of traffic entry of this information; however, operators who perform
slowdowns. The sources for event and incident data are typi- the entry often do not know the daily plans for specific clo-
cally from one of two categories: sures. This is just one example of a challenge with keeping
FIGURE 21 Reporting frequency of events and incidents.
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manual entry of events updated and detailed enough to ben- OnStar operations center (together with the vehicle location
efit travelers. and in many instances a description of the crash characteris-
tics). A voice connection is automatically established to the
In the survey conducted within this project, every respon- vehicle and the OnStar operator speaks with the passengers. If
dent indicated they had a manual system for entering con- the OnStar dispatcher determines that emergency services are
ditions and event information. Responders were asked how required, they are able to push a button to automatically estab-
often events and conditions are entered, and the results are lish a three-way communication with the local Public Safety
summarized in Figure 21. Answering Point. At the time this three-way phone connec-
tion is established, the data describing the vehicle location,
Responders who entered "Other" to the question pre- description, and any available crash statistics is transmitted to
sented in Figure 21 were asked to comment. The comments a national data router. These data are received and used by a
received are summarized here: number of states, both to support emergency response (as the
vehicle location can be plotted on an on-screen map) and to
· Varies by season (winter is reported as conditions include in traveler information dissemination.
change and are reported from the field personnel and
summer is updated weekly or as project info changes). Some of the technical challenges to automated system-to-
· Varies; we try for two to three times daily but often system data exchanges are summarized as follows:
outstate staff fail to do it.
· 24/7/365 in Northern Nevada. So NV calls in to ops · Data consistency. Often, the entry of incidents is done
center in Reno to update major/critical events only. using free text entry into CAD systems, and therefore
· Several times per day from 4 a.m. to 9 p.m. can be a challenge to extract, format, and insert into a
(OctoberApril). condition reporting system that supplies data to trav-
· October through May: MF early a.m. Sometimes eler information systems.
updated in the afternoon and provided on weekends. · Institutional. Institutional challenges associated with
June through September: only report if adverse weather sharing incident data may cause some emergency pro-
conditions exist. viders to not share their data. Often, the removal of any
personal information and simply reporting the traffic
Automated System to System Data Exchanges impacts can reduce these institutional challenges.
· Need for verification. As an example, WSDOT has
Automated Exchanges of Incident Data a policy that they disseminate information only about
events that are verified by DOT staff. Some incident
Another popular approach to assemble event and incident reports received from emergency response CAD sys-
information is through automated data exchanges with other tems may not have been verified (e.g., a cellular 911
systems. Recently, several federally funded projects have caller may report seeing a vehicle stalled and block-
deployed automated systems to exchange incident informa- ing a lane and this may be entered into the CAD sys-
tion that is stored in emergency response or law enforcement tem; however, when a responder arrives on the scene,
computer-aided dispatch (CAD) systems with transportation the vehicle has cleared). Because CAD events are not
information dissemination systems. These systems help to always verified, WSDOT performs some form of a
avoid the need for duplicate entry of events and are based on manual review of the incidents received from external
the understanding that the law enforcement or emergency CAD systems, and therefore requires operator input.
response agencies enter descriptions of crashes and incidents · Data Sharing. Beyond the institutional issues men-
into CAD systems to facilitate response. Rather than ask tioned in the second bullet, data sharing challenges
these dispatchers to reenter incident descriptions, automated may include legal challenges that prevent data sharing
data exchanges have been developed. Systems that include or technical challenges such as firewall barriers.
this automated data exchange have been developed (and are
operational) in Salt Lake City, Utah, and Washington State. Automated Exchanges of Construction Data
Another successful example of automated data exchanges Another example of possible automated data exchanges is
is a relationship established with the OnStar services. Today, construction and maintenance reports. Maintaining current
a number of states receive automatic reports from the OnStar and useful construction information with daily updates is
service center any time a vehicle has an air-bag deployed and a challenge. With increasing numbers of electronic con-
emergency services are notified. The way the system works struction and maintenance planning tools, interfaces can be
is that active OnStar-equipped vehicles that are involved in developed to share planned activities with traveler informa-
a collision that deploys the airbag send a notification to the tion systems.
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Survey Input on Automated Data Collection 9. CHP CAD incidents are fed automatically to the
Advanced Transportation Management System.
Responders to this project's survey were asked to describe
any automated data sources for crash and incident data. The Coordinating Information from Several Sources
comments received are summarized as follows:
As described in this chapter, traveler information systems
1. CAD systems or automated systems are not employed often disseminate information obtained from multiple
at this time. sources. This information may describe either different
topics (e.g., weather information from one source and trav-
2. OnStar feed provided by the Condition Acquisition el-time information from another source) or the same topic
and Reporting System consortium. (e.g., travel-time information from internal to the DOT
and travel-time information from an outside service pro-
3. None. vider). Based on the survey of operational traveler infor-
mation websites, the most common approach is to present
4. No automation but are working with developer for data obtained from several sources together, taking steps
automated CAD entries. to normalize the data as much as possible and present a
universal picture of the travel situation. Simply put, trav-
5. CAD is used. Also, the freeway flow map is an indi- elers are not going to understand the various sources of
cator of possible trouble when a segment turns red or the data, and the industry-wide approach appears to be to
black when normally at that time it is green or yellow. amalgamate the data.
So if the colors change then the TMC operators can
use the cameras to figure out the cause of the nonstan- The coordination of information topics does raise another
dard congestion. issue regarding the normalization of data. As public agen-
cies move from first- or second-generation traveler infor-
6. Currently, NC receives data from our State Highway mation systems to later-generation systems, consideration
Patrol. should be given to a more formal data and information nor-
malization process that begins at the data collection phase.
7. Our operators MANUALLY enter incident informa- The accuracy, precision, recording procedures, and time
tion from the California Highway Patrol (CHP) CAD. frame for which the data are valid can all be normalized.
The result will be a situation that more accurately compares
8. CHP CAD. We are seeking to build a "TMC Activ- "apples to apples" and presents more unified information to
ity Log" and to gain statewide use of "lane closure the travelers.
reporting system."
