What Is It?

• Under manual surveillance, wireless phone users call into a Transportation Management Center (TMC) or Traveler Information Center and report incidents or traffic conditions. See our Telecommunications Diagrams on Cell Phone-based In-Vehicle Traffic Advisories and Traffic Surveillance Using Cell Phones for more information.
• Under automatic surveillance, wireless service providers automatically collect geo-location data of wireless phones and forward it to TMC's.
• Automatic wireless surveillance has not yet been implemented but is in the process of being tested in a few select sites.

Key Results

Manual Surveillance Several DOTs and local transportation authorities have implemented programs that allow drivers to call and report incidents from their cellular phones. Evaluations have found cellular detection to be effective, and that a large proportion of major incidents are first identified from cellular reports. Generally, about two-thirds of calls provide new information, while about a quarter are duplicate calls, providing previously received information. Other benefits include the reporting of malfunctioning traffic signals, debris in the roadway, and other incident causing conditions. Cellular detection is most effective during peak periods when coverage is highest.

Automatic Surveillance
Wireless geo-location information has the potential to advance traffic management efforts significantly at a fraction of the cost that would be required to implement conventional intelligent infrastructure. Impetus for wireless surveillance is the result of the FCC's impending E911 regulations requiring wireless phones to incorporate geo-location technology (GPS), to allow for the accurate location of wireless 911 calls.

Vehicles with active wireless phones can dramatically extend the existing surveillance range (the percentage of new vehicles with wireless communications will exceed 50% within 5 years and will reach 100% within 10 years. Wireless phone acquisition is also booming). Further, this could yield usable information on arterials that may have been more difficult and costly to obtain from conventional intelligent infrastructure. Benefits for traffic management, in a relatively short timeframe, are potentially large yet cost and implementation issues to allow data retrieval are not negligible.

Benefits

• Immediate coverage of the entire roadway, with no capital and maintenance costs to transportation agencies.
• Elimination of or drastic reduction in the need for fixed detection surveillance investments.
• Higher reliability of data.
• Data can be provided on link travel times to allow travel time estimation.
• Data is provided regardless of road surface and weather conditions unlike other detection technologies.
• Data can complement and be integrated with existing data from other surveillance technologies.
• Automatic archiving of geo-location incident data in historical databases can allow for the development of preferred response plans as well as corrective and preventive measures for problem spots.
• Widespread coverage would also dramatically improve dynamic route guidance. This would be particularly beneficial in emergency response situations.

• Communications services and equipment (hardware and software) to allow data retrieval, processing and response. This will imply both modification of existing TMC systems, the installation of new communication systems, and on-going maintenance. These costs could be significant as new software and hardware will be required as well as modification of existing system databases, detection and congestion algorithms, alarm generators and communications interfaces.

• Implementation costs that could be significant. Also, TMC's would be funding this through operational expenditure that is relatively scarce and often re-appropriated on a yearly basis, thus making long-term operational commitments for wireless data retrieval challenging.
• Technical obsolescence and limitation: wireless phone technology is changing at a very rapid pace and there are several wireless standards so the issue of future compatibility should be considered carefully when investing in current technology. Changes in urban geography (i.e. high-rises along freeways) could affect data accuracy and latency imposing recalibration costs.
• Standards:
  • Evolving wireless phone standards could cause implementation challenges. Currently there are several standards: AMPS (a first-generation analog cellular), GSM (digital cellular) TDMA (digital cellular, narrow band), CDMA (digital cellular, wide band) and 3G (third generation cellular systems refer to currently developing next generation cellular technologies). For more information on wireless developments and standards as they apply to ITS visit our Telecommunications section.
  • There is currently no standard, although efforts are underway, for geographic reference location. Currently TMC's work from route number and mile marker not latitude/longitude. Speed data formats will also be required.

• Currently pilot projects are underway in the U.S. and in France.
• Baltimore/Washington D.C. area: Maryland State Highway Administration and FHWA have a contract with U.S. Wireless to provide wireless surveillance.
• Hampton Roads/Virginia Beach, Virginia: U.S. Wireless, Iteris and other private entities have partnered to develop a wireless geo-location ATIS system to the Virginia D.O.T.
• Lyon, France: SFR (the 2d biggest GSM carrier in France), ASF (the largest toll company in France) and INRETS (The French institute of transportation research) are teaming under European project SERTI (Co-ordination of ITS Implementation in Southern Europe) to test cell phone surveillance on a 100 mile stretch of freeway south of Lyon.

Author: Dimitri Loukakos