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TRIMARC is part of a national initiative to deploy Intelligent Transportation Systems (ITS) to 75 of the nation's largest metropolitan areas. It includes an integrated system of sensors, cameras, dynamic message signs, highway advisory radio and computers monitoring more than 100 miles of interstate traffic in the greater Louisville and Southern Indiana urbanized area. Northrop Grumman is the system integrator and operator for TRIMARC. Northrop Grumman designed and manages the Louisville control center that collects information on traffic flow, construction areas and accidents. Once collected, the information then is disseminated to motorists via dynamic message signs and highway advisory radio.

TRIMARC Control Center
TRIMARC Control Center

This website offers this information and provides real-time streaming video of eight area interstate corridors. This site also offers traffic flow conditions and estimated travel times. In addition to dynamic messaging and web-based communication, information is available on government access television, thanks to a morning traffic program produced in cooperation with Louisville Metro TV Channel 25 and Northrop Grumman.



Apply Technology, Processes, and People to Improve Transportation.

The purpose of TRIMARC is to improve the performance of the existing Freeway system in the Metropolitan Louisville and Southern Indiana area. This is accomplished by implementing services and systems that facilitate the efficient flow of traffic. A key to this concept is the dissemination of information to the public as well as the officials who are responsible for managing and maintaining the transportation infrastructure.

Through the use of roadway sensors, video monitoring, variable message signs, and highway advisory radio, drivers are quickly alerted with these advanced warning systems. Northrop Grumman software analyzes the sensor data and pinpoints potential problems to the operators who use the cameras for verification. These warning systems help travelers avoid delays, plan alternate routes and enhance their travel experience. By increasing the availability of information on the real-time status of traffic, TRIMARC is realizing improvements in the response time to incidents, preventing the occurrence of secondary incidents and improving air quality through the reduction of traffic congestion.



TRIMARC is funded through a cooperative effort between the Kentucky Transportation Cabinet (KYTC) and the Federal Highway Administration. Northrop Grumman has been the contractor responsible for developing the design, installing the systems and software, and operating and maintaining the equipment since project inception. Key contractor team members include TEC, Samaritania, Wilbur Smith Associates, and Bluegrass Electrical Consultants; and in association with Global Solutions LLC, HDDS Inc., J.Y. Legner & Associates, ClasSickle, Inc. and Redwing Ecological Services, Inc.. This process began in 1998 and is continuing to move forward with expanding coverage to outlying highways in the Metropolitan Louisville and Southern Indiana area as funding becomes available.


Intelligent Transportation Systems

ITS encompasses a broad range of modern computer and communications technologies. When integrated into the transportation system infrastructure or in vehicles, these technologies help monitor and manage traffic flow, reduce congestion, provide improved mobility, safety, air quality, and productivity. TRIMARC is an example of ITS.

For more information on ITS visit the ITS FAQ.


Roadway Sensors

Vehicle detection technologies form the foundation of the freeway management surveillance system. Control strategies, incident management procedures, and motorist information displays are selected based upon real-time data collected by traffic flow sensors. Data may include vehicle speed, traffic counts, lane occupancy, vehicle classification, changes in vehicle motion and position, traffic density, travel time, vehicle length, acceleration characteristics, and in some cases, vehicle location and hazardous material status.

WBR Two separate approaches to vehicle detection exist: those that are infrastructure-based, and those that require both in-vehicle and infrastructure-based devices. Most current ITS vehicle detection systems do not require in-vehicle devices. These systems allow for the evaluation of the performance of the transportation network by TOC personnel, as well as monitoring the freeway system for irregular conditions and levels of congestion.

TRIMARC primarily uses Microwave Radar Vehicle Detectors (MRVDs) and loop detectors and controllers for their roadway sensors, but have employed a few VVDS.

Enhanced Reference Markers

Blue Reference Markers located every 1,000 feet along the roadway provide emergency response teams with the exact accident location. Studies have shown that these enhanced reference markers save time in identifying locations of disabled motorists and improve emergency response times to highway incidents. The signs were designed to be easily visible and include the direction of travel with an interstate shield identifying the interstate name above the mile marker number. The mile marker number designates a specific location on the interstate in relation to the state border. The top number is the number of miles while the bottom number represents tenths of a mile. Reference Marker

Closed Circuit Television Cameras

Closed circuit television cameras (CCTV) have proven to be one of the most valuable elements of a freeway management system. They facilitate visual verification by a traffic operations center (TOC) and enable emergency-response personnel to confirm reported incidents and/or other traffic conditions. This helps provide efficient evaluation of incident severity and confirms appropriate personnel and response vehicles that should be dispatched to an incident scene.

CCTV serve three separate functions; improve incident response, assist with traffic management, and provide traveler information. Emergency personnel at the TOC can observe incidents visually and assess the proper response. TOC personnel can better manage the flow of traffic by displaying messages on DMS and broadcasting messages on HAR as a result of their ability to view the covered area of the freeway system. The CCTV system can be used to provide video to the public via websites or television media for broadcasting. CCTV

Dynamic Message Signs

Message Signs provide timely information to motorists of any upcoming incidents and estimated delay times. Message signs are available for freeway management applications and are referred to as Changeable Message Signs (CMS), Variable Message Signs (VMS), or Dynamic Message Signs (DMS). Vendors often claim that these names indicate different functionality or capability. However, the basic functionality of each is the same because these signs are all used to convey dynamic information to the motorist in text or graphics formats.

TRIMARC primarily uses fixed dynamic message signs that are capable of displaying 2 frames of text, with 3 lines of up to 21 characters. TRIMARC also has several smaller portable VMS's used for special events or long term incidents.


Highway Advisory Radio

While dynamic message signs have a significant impact in informing motorists, they are only effective when an incident is beyond the signs' locations and are somewhat limited in the amount of information that can be conveyed to the motorist. Therefore another communications aspect of the freeway management system is the use of Highway Advisory Radio (HAR). HAR provides information over a wider area and provides the opportunity to convey more detailed information such as alternative route directions. Motorists in the receiving area would be advised to tune to the appropriate frequency by the dynamic message signs and/or by a network of static signage with flashers activated when there is a traffic alert.

HAR Flasher HARs are effective when used for long-term construction zones where a significant amount of detailed information must be conveyed to the motorist especially if providing alternate route information. HARs are also effective in handling special events where directions to exits and parking areas can be provided to motorists. Traffic information can be recorded for playback by the HAR system at the appropriate time for motorists to listen to the selected channel as they pass through the targeted geographical area. Various levels of complexity in the hardware are available which may lend themselves to differing degrees of flexibility in the programming of information for the motorist. HAR systems can utilize one longer message that can be recorded daily or multiple messages can be stored in playlists for playback as needed.

HAR systems are used to disseminate information to the motorist over a limited range via AM radio channels. Licensed and unlicensed systems exist as well as fixed or portable models that cover a 0.25 - 5 mile radius. TRIMARC, in cooperation with the Louisville Metro Emergency Management Agency, operates on 1610 AM in the Louisville Metro area. Most DOTs operate non-licensed AM stations. Detailed frequency propagation analysis must be performed to determine the optimum location and frequency for each installation.


Auto Incident Recording System (AIRS)

As part of the TRIMARC program in Louisville, Kentucky, Northrop Grumman deployed a revolutionary Auto Incident Recording System (AIRS) to provide data for the monitoring and analysis of a dangerous intersection. Initially deployed in June 2001 at the intersection of Jefferson and Brook in Louisville, the system was used to characterize the intersection. Based on analysis of the data, intersection modifications were identified and implemented. Analysis of data collected after the intersection modifications identified an 80% to 90% reduction in near and actual incidents at the intersection since modifications were implemented. At the request of our customers, the AIRS system has recently been deployed to the intersection of Taylorsville Road and Hikes Lane. This program now provides Louisville Traffic Engineers the technology and information to analyze "high-incident" intersections and design changes to improve safety. Based on the work accomplished on this system, the TRIMARC program was selected for the 2002 Best of ITS Award in Research and Development.

AIRS at Brook & Jefferson

AIRS monitors an intersection with two cameras and microphones listening for the tell-tale sounds of a collision or near collision; metal-against-metal contact, broken glass, squealing brakes, etc. The cameras continuously record to an 8-second digital memory loop. Once the system "hears" an apparent collision, another 4 seconds of video capture occurs. Then the 8-second loop is dumped to a video recorder capturing sights and sounds of the intersection 4 seconds prior to the collision and 4 seconds after the collision. AIRS also captures intersection signal phase by monitoring the current to the signal head and pedestrian signs. The traffic engineer then encodes this signal data with the recorded video for review. One benefit of AIRS is the ability to detect and capture near-incidents triggered by squealing tires. This data allows the traffic engineer even greater insight into the traffic patterns and driver habits at the intersection.

Originally developed by an engineer at Mitsubishi Electric as aid to golfers, a camera and recorder were setup to view a golfer's swing while a microphone listened for the distinctive sound of the club against the ball. By recording only several seconds before and after contact, the system made the most effective and efficient use of the recording system and the time to view the golfer's swing.

The system was further enhanced by Mitsubishi Electric for monitoring intersections and is currently being deployed to over 300 intersections in Japan. The system in Louisville is the first installation in the United States under the TRIMARC program. The Kentucky Transportation Cabinet is the contract manager for the program while Northrop Grumman is the system integrator responsible for the design, installation, and operation of the system.


Condition Acquisition and Reporting System (CARS)

The Condition Acquisition and Reporting System (CARS) is a non-proprietary, standards based condition reporting system that allows authorized users the ability to enter, view and disseminate critical road, travel, weather and traffic information. CARS users can access the system from any location using a standard web browser. This allows users to enter condition reports or view reports entered by other users around the state of Kentucky. TRIMARC, as a Kentucky Transportation Cabinet project, is a key contributor to CARS for incident information in the Louisville Metro area. Currently, thirteen states have deployed the CARS system including Kentucky. For more information on CARS visit the CARS Program website.


511 Telephone Service

Another useful traveler information technology is the 511 Telephone systems, which was ordered by the Federal Communications Commission (FCC) in July of 2000. This technology offers motorists the ability to select the information they receive in terms of route and mode. The FCC order provides a consistent telephone number for public use and also the flexibility to configure systems to meet the needs of each state and local agency. Accessing the 511 system is free to callers in Kentucky and most other states.

Route specific traffic information is collected for playback on the 511 Telephone system at the request of the caller. In order to evaluate the service and functional needs of the 511 Telephone system one must consider the areas that are likely to be compared for consistency on a national level.

These areas include:
  • System Navigation
  • System Access Quality
  • Initial Greeting
  • Advertising/Sponsorship Rules
  • ADA Compliance
  • Hours of System Operation
  • Multi-lingual capabilities
  • Timestamp information
  • Roadside Signing
  • The FCC plans to review the progress of 511 deployments with a key part of this review focusing on the consistency of the 511 services.


    WIZARD Warning System

    WIZARD Warning System Another safety feature of TRIMARC is the WIZARD warning system. I-65 has a curve in the hospital district of Louisville where loads on trucks have been known to suddenly shift and cause an accident. The WIZARD system listens for "dead" air on CB channel 19 and then broadcasts a warning every 90 seconds to truckers making them aware of the approaching curve.

    Technical comments or suggestions should be submitted either by writing to:
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    Louisville, KY  40202
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