# Intelligent Transportation Systems           in Work Zones

## A Case Study

### Work Zone Traffic and Incident Management System

### Keeping Traffic Moving During Reconstruction of the Big I,           a Major Interstate-Interstate Interchange in Albuquerque

#### January 2004

**Notice**

## Foreword

Dear Reader,

We have scanned the country and brought together the collective wisdom         and expertise of transportation experts implementing Intelligent Transportation         Systems (ITS) projects across the United States. This information will         prove helpful as you set out to plan, design, and deploy ITS in your communities.

This document is one in a series of products designed to help you provide         ITS solutions that meet your local and regional transportation needs.         The series contains a variety of formats to communicate with people at         various levels within your organization and among your community stakeholders:

- Benefits Brochures  let experienced community leaders explain           in their own words how specific ITS technologies have benefited their           areas;
- Cross-cutting Studies  examine various ITS approaches that           can be taken to meet your community's goals;
- Case Studies  provide in-depth coverage of specific approaches           taken in real-life communities across the United States; and
- Implementation Guides  serve as "how to" manuals to           assist your project staff in the technical details of implementing ITS.

ITS has matured to the point that you are not alone as you move toward         deployment. We have gained experience and are committed to providing our         state and local partners with the knowledge they need to lead their communities         into the next century.

The inside back cover contains details on the documents in this series,         as well as sources to obtain additional information. We hope you find         these documents useful tools for making important transportation infrastructure         decisions.

Sincerely,        Jeffrey F. Paniati        Associate Administrator for Operations        Acting Program Manager, ITS Joint Program Office        Federal Highway AdministrationPreface
This case study is one in a series of documents that examines the use         of Intelligent Transportation Systems (ITS) in work zones. More information         on this system and other applications of ITS in work zones is available         in the companion document, *Intelligent Transportation Systems in Work         Zones — A Cross-Cutting Study* (Report No. FHWA-OP-02-025,         EDL# 13600).

This case study reflects information gathered in interviews with key         personnel on the Big I construction project in Albuquerque, New Mexico,         as well as information and photos obtained during a site visit. The authors         greatly appreciate the cooperation of the New Mexico State Highway and         Transportation Department and its partners, who made the production of         this document possible.
 Contents - Project and System Background
- System Design, Selection, and Implementation
- System Description and Operations
- Results
- Conclusion
Project and System Background
The New Mexico State Highway and Transportation Department (NMSHTD) rebuilt         the Big I interchange in Albuquerque to make it safer and more efficient         and to provide better access. The Big I is where the Coronado Interstate         (I-40) and the Pan American Freeway (I-25) intersect in Albuquerque.         The original Big I was designed to support an average daily traffic (ADT)         of only 40,000 vehicles and was severely over capacity, experiencing an         average of 1.7 crashes per day that were estimated to cost about $12 million         annually (data from 1999). ADT in the interchange was approximately 300,000         vehicles prior to its redesign; the redesigned Big I has a design capacity         of 400,000 ADT. The two-year project began on June 30, 2000 and involved         111 lane-miles of construction and 45 new and 10 rehabilitated bridges.

For the Big I project, NMSHTD employed ITS in the form of a mobile traffic         monitoring and management system to help move the large number of vehicles         through the extensive construction area. Mobile traffic monitoring and         management systems use electronics and communications equipment to monitor         traffic flow and provide delay and routing information to drivers and         agency personnel. The ITS application deployed at the Big I in 2000 was         used for the duration of the work zone (two years). The ITS components         were deployed just prior to construction, with plans to incorporate portions         of the system as part of a permanent ITS application for freeway management         once construction was completed. Figure 1 shows some of the ITS equipment         deployed at the Big I.
Figure 1 — Example of ITS equipment deployed         at the Big I.
NMSHTD used ITS for this major construction project for several reasons,         including:
- Changes in traffic patterns, nighttime closures, and pre-determined           alternate routes required that travelers be provided with high-quality           real-time information on travel route availability.
- The high volume of traffic moving through the Big I created great           potential for congestion. NMSHTD estimated that normal traffic volume           had to be reduced by at least 20 percent to keep traffic moving through           the Big I area. Incidents would create further congestion and require           rapid response to avoid additional delays. A system was needed to provide           accurate information, support quick identification of incidents, and           help manage traffic through the area.

The main goals of the ITS were:
- To provide traffic management capabilities and traveler information           on traffic routing, detours, and significant incidents.
- To minimize capacity restrictions due to incidents by more quickly           identifying incidents and determining an appropriate and effective response           to clear the roadway.
- To enhance traveler safety.

The Big I ITS included a series of cameras and sensors to monitor traffic         conditions and detect incidents, and electronic signs, highway advisory         radio (HAR), a website, and other media to transmit traveler information.         The incident detection capability was a major component of the system.         To effectively use the system information to expedite incident clearance,         NMSHTD made use of its motorist assistance program.
***"ITS has been a very essential and integral         part of the Big I Construction Project."**— Rhonda Faught, Secretary, New Mexico State         Highway and Transportation Department*Figure 2 — Highway Emergency Lender Patrol Vehicle
Instituted prior to the Big I project, the Highway Emergency Lender Patrol         (HELP) program consisted of two vehicles patrolling the Albuquerque Metropolitan         area. NMSHTD recognized that the Big I project would require more HELP         trucks. The Federal Highway Administration provided $250,000 toward the         purchase of two additional HELP trucks. The additional vehicles were purchased         through the construction contract to help patrol the Big I project area         during construction. The original two HELP trucks were then able to patrol         the rest of the Metro area.
- The contractor was given (on a no-cost lease) two HELP vehicles           to operate Monday through Friday from 5:00 am to 8:00 pm to patrol the           work zone during construction.
- The HELP trucks are equipped with an air compressor, arrow board,           assorted tools and a truck-mounted attenuator             (see Figure 2).
- The HELP vehicles provided assistance to more than 10,000 stranded           motorists during the two years it took to rebuild the Big I.
- At the end of the Big I project, the HELP Trucks were turned over           to the NMSHTD for continued use.
Back to TopSystem Design, Selection, and Implementation
This section provides information on NMSHTD's experience in bringing         the system from the concept stage to fully operational.
In-House or Contractor Design- NMSHTD used a design contractor for the Big I reconstruction project.           The design contract had a task for construction oversight that included           design and implementation of a work zone ITS.
- NMSHTD felt that it would be best to use a contractor with experience           in designing an ITS system for complex projects such as the intersection           of two large interstates.
System Selection and Procurement- The design and construction oversight contract called for the purchase           and installation of all components of the ITS system as a lump sum purchase.
- The design contractor let a subcontract for the ITS system. The subcontractor           provided all system components, software and installation.
- Partial payments were made to the contractor as the system was deployed,           and for Cellular communication charges, but final acceptance and full           payment did not occur until the end of construction.
- NMSHTD assumed ownership of all components of the system at the end           of construction.
- The total cost of the ITS system was $1.5 million.
Lease Versus Purchase- Some of the ITS work zone system components were designed to be part           of a permanent freeway management system after construction. Therefore,           the State decided to purchase the system components as opposed to leasing           them.
- Purchasing the system required greater capital costs early on, but           funding was available for this option.
- The design contractor purchased the system through their contract           for NMSHTD. The ITS system was purchased using construction oversight           funding.
System Implementation- The design contractor provided a draft implementation/configuration           plan to NMSHTD that was based on their previous experience and tailored           to the characteristics of the Big I reconstruction project. NMSHTD staff           then reviewed and revised the implementation plan.
- The initial deployment phase lasted longer than anticipated due to           larger than expected variations in traffic volume during the system           calibration phase.
- The system took three and a half months to deploy from concept to           full installation and operation. Setup time included three days per           location to set up each VMS and camera, and half a day to set up each           portable Smart Zone.
Testing- The system was designed to be portable and use wireless communication.           Wireless communication links were tested prior to the installation of           field elements to ensure adequate bandwidth availability.
- The complete system was brought online two weeks prior to the start           of construction. This allowed for thorough pre-construction testing.
Training- The vendor trained NMSHTD employees on the use of the system and its           capabilities so that they would be able to continue to operate it in           the future.
- After the training, NMSHTD employees staffed the temporary Big I traffic           management center (TMC), with periodic consultation with the vendor.
Back to TopSystem Description and OperationsSystem Description- The system consisted of eight cameras; eight modular (expandable)           dynamic message signs (DMSs); four arrow dynamic signs; four all-light           emitting diode (LED) portable DMS trailers; four portable traffic management           systems, which integrate cameras and DMS on one fully portable unit;           and four HAR units, all linked electronically to the temporary Big I           TMC.
- Components relied on solar re-chargeable systems for power (see           Figure 3).
- Communications equipment for the system included spread spectrum radio,           wireless Ethernet applications, and cellular digital packet data (CDPD)           modems. 1
Figure 3 — Solar-Powered Sensors and Communication         EquipmentSystem Operations- NMSHTD employees staffing the TMC monitored camera displays from 5:00           am to 8:00 pm, Monday through Friday to detect incidents             (see Figure 4).
- The staff were able to:             - Notify emergency personnel for dispatch.
  - Post messages on electronic roadway signs.
  - Provide traveler information to the public via the Internet and               a pager network. 

The information provided was based on the incident type and severity.
Figure 4 — The Big I TMC System Description and         Operations- NMSHTD also distributed information via a website, media outlets (radio,           newspaper, television), pagers (provided by a commercial paging service),           and fax and email distribution lists.
- Camera image data for the system were provided by electronic means,           and system components were connected via wireless infrastructure to           allow for data flow from the field to the TMC.
- The system software held a set of message scenarios for the electronic           roadway signs. Because the core of the Big I was entirely closed to           traffic most nights to facilitate roadwork, a whole series of detour           messages needed to be displayed each night. The ITS enabled TMC operators           to activate a pre-defined message scenario for all the DMSs with           "one click." These scenarios were not set to activate automatically,           although they could be. During incidents, NMSHTD could also manually           activate DMS messages indicating the accident location, lanes affected           and whether delays were occurring. The amount of delay and length of           queue were not displayed.
- The concept of operations diagram for the system is shown in Figure           5.
- The Big I website was updated regularly with new information. The           website displayed camera images in real-time and updated them automatically,           providing the public with current, timely information. NMSHTD manually           refreshed much of the other website content on a weekly basis.
Figure 5 — Albuquerque Work Zone ITS Concept of Operations Diagram***"We have received scores of thank         you letters and emails from the public."** — Rhonda Faught, Secretary, New Mexico State         Highway and Transportation         Department regarding the Big I website, which provided the public with         real-time camera images.*Contractor or Agency Staff- State agency staff operated the Big I ITS and its TMC.
- NMSHTD consulted subcontractor personnel on an "as-needed"           basis for assistance with technical issues. This assistance was provided           through the construction oversight task of the design contract.
Coordination with Key Personnel, the Public, and Other Agencies- NMSHTD used a proactive traffic incident management approach. NMSHTD           staff developed a Crisis Communication Plan that delineated coordination           procedures to be followed, for various types of incidents, by key personnel,           the public, and other agencies as needed.
- Contact information posted on the project website allowed the public           to voice opinions on the functionality of the system and also identify           any problems.
- Faxes were sent out (at least weekly) to inform the media and other           agencies about road closures, detours, schedule changes, and major incidents.
- A police substation was located in the general contractor's staging           yard as shown in Figure 6, allowing for quick access and response to           the construction area. A police base station radio deployed at the TMC           allowed for direct communication between the police and NMSHTD staff.           A dispatcher was co-located in the TMC to dispatch the officers           as needed. An emergency medical technician (EMT) unit and a tow truck           were also located in the same compound as the police substation.
Maintenance- NMSHTD performed periodic, as-needed maintenance on system components           with some initial help from the subcontractor.
- The subcontractor provided a warranty on all equipment for one year           from the date of purchase. However, NMSHTD needed to cover the maintenance           aspects of equipment problems and removal and installation of new parts.           Therefore, NMSHTD decided to purchase spare parts and perform maintenance           in-house.
Figure 6 — The Big I Police Substation in the         General Contractor's Staging YardBack to TopResultsSystem Performance- The ITS construction TMC participated in about 500 incident responses           per month during construction.
- Incidents in the construction zone ranged from stalled vehicles to           multi-vehicle injury crashes.
- Visual coverage of the construction zone traffic resulted in average           response times of less than seven minutes with average clearance times           of less than 25 minutes.
- The system functioned properly approximately 95 percent of the time.           Operational issues were typically resolved within 48 hours of detection.
System Evaluation- NMSHTD evaluated the ITS system through surveys of public perception,           and through the measurement of impacts on crash frequency and incident           response and clearance times. Results are noted below.
Benefits/Impacts
NMSHTD staff identified three major benefit areas resulting from the         Big I reconstruction project, which are listed below.
 Mobility- Incident response and clearance time was reduced from 45 minutes (historically)           to 25 minutes in the work zone with ITS.
- Approximate reduction in traffic as experienced from travel demand           management techniques (outreach, public communication, etc.) was 15           percent.
- Information provided by the system allowed NMSHTD to determine the           appropriate response for an incident, allowing the correct number of           emergency services and motorist assistance vehicles to be sent. This           both saved money and minimized the decrease in roadway capacity.
Safety- A 32 percent reduction in crashes was observed during the first three           months of the work zone (compared to the previous year).
- Over the entire first year of the work zone, crashes were seven percent           higher than the previous year without the work zone. This increase was           smaller than what NMSHTD expected with the complexity of the work zone.
- The reduced incident response and clearance time is believed to have           resulted in a reduction in the frequency of secondary crashes. Other           motorists were less distracted by incidents, and "rubbernecking"           was reduced due to the shorter clearance time.
- Driver behavior observed using the system cameras allowed NMSHTD to           identify areas where drivers were having difficulty navigating the work           zone. This information was then used to make work zone configuration           changes to improve traffic flow.
 Cost Savings- Most nights the core of the Big I was closed to traffic, and detours           were activated. Daytime traffic patterns through the work zone also           changed frequently. The operator could activate pre-programmed           message scenarios with a few keystrokes without leaving the TMC. This           automation saved NMSHTD considerable effort in informing travelers of           changes in the work zone and detours.
- One person at the TMC could monitor work zone operations and disseminate           information to the public and incident response personnel.
- System information allowed police, fire and emergency personnel to           assess incident severity and send the correct number of vehicles. Thus,           costs were reduced, and other units were free to respond to other incidents.
Public Reception/ Reaction to the System- NMSHTD administered over 1,000 surveys to assess the public's           perception of the Big I ITS.
- More than 60 percent of survey respondents were pleased with the accuracy           and timeliness of the public information provided.
- NMSHTD found that the use of the system lead to improved communication           and an improved relationship with the public.
Obstacles Encountered and Lessons LearnedGeneral- System Communications:  Systems need to have reliable communications.           The communications network for an ITS application is vital to the operation           of the system and must be reliable. Issues that may impact communications           need to be addressed early in the system development and deployment           process.
- Start-Up Time:  It is important to allow start-up           time when deploying a system. Problems will arise — such as with           sensor operation, communications (wireless or wireline), license applications,           component calibration, hardware, or software — and will take time           to address. NMSHTD found that a full service maintenance warranty would           be too expensive to be practical (on the order of $100,000), so they           invested the time to learn about maintenance of the system and performed           maintenance in-house.
- Building Public Awareness:  It is important to use a proactive           approach in building public awareness of the project and the information           that the ITS application will provide. Successful techniques include           holding press conferences, issuing news releases, and keeping local           media (especially those the public turns to for traffic information)           up to date. NMSHTD used public meetings and outreach to reduce travel           demand during the work zone period.
- Accuracy of Information:  It is vital to deliver accurate information           to the public. If inaccurate information is provided, the public can           quickly lose confidence and negative public relations result. NMSHTD           performed outreach to the public to help educate motorists and travelers           and for travel demand management.
- Interagency Coordination:  Other stakeholder agencies, such           as those responsible for incident management, need to be involved early.           Coordination with other agencies is a primary issue that agencies should           consider both in developing and implementing an ITS work zone system.           NMSHTD coordinated extensively with the incident management community.           FHWA assistance for incident management was obtained to help patrol           the work zone area.
- Information Delivery:  It is important to carefully consider           how to set up automated information delivery and sharing with other           agencies. It is possible to deliver too much information for agencies           to process effectively.
Planning and System Development- Relating with Other Agencies:  State departments of transportation           need to "sell" ITS to the incident management community and           work with them to determine how to use the system to coordinate with           incident response.
- System Features/Capabilities:  Portability of the ITS units           is key in the core of the work zone because the work zone configuration           changes frequently, which may require that the units be moved.
Communications- Communications Capacity:  For CDPD communication, it is important           to ensure that the cellular provider has sufficient unused capacity           to eliminate communications failure during peak cell phone usage hours,           due to service overload.
System Deployment- Start-Up:  It is important to use a proactive approach           to building public awareness of the project and the information that           the ITS application will provide. Successful techniques include holding           press conferences, issuing news releases, and keeping local media up           to date.
- Access/Security:  It is necessary to allow for access to sensor           stations for maintenance.
System Operations- Use of System Information:  When changes in work zone roadway           geometry are made, it is important to allow time for drivers to learn           the new traffic pattern before reporting problem spots to the contractor           based on observations from the system's cameras.
- Power Supply:  Stations may need to be reset manually when there           are power interruptions, such as lightning storms.
- Maintenance:  Maintenance needs can be met in-house, with           help initially from the vendor.
Back to TopConclusion
The use of ITS for the Big I proved to be very successful in mitigating         the effects of construction on traffic mobility and safety. The NMSHTD         plan called for the use of ITS during construction, and also allowed some         of the system components to be made a permanent part of the freeway management         system for the Big I. This case study is one example of how ITS is being         implemented across the nation to help agencies better manage traffic while         performing necessary infrastructure improvements.
***"I don't think that we could have         maintained the traffic flow we had through the Big I without the ITS."**— Rhonda Faught, Secretary, New Mexico State         Highway and Transportation Department*Back to TopFootnotes
1 Note: CDPD is being phased out as most cell networks are         migrating to GPRS/GSM (General Packet Radio Service/Global System for         Mobile communications) digital.
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Back to TopThis Document Is One in         a Series of Products That Address ITS Issues Pertinent to a Variety of         Audiences- Elected and Appointed Officials
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**Benefits             Brochures** quote how ITS technologies have benefited specific areas.**Technical             Reports** include results from various Field Operation Tests.**Cross-Cutting             Studies** present current data from related ITS applications.**Implementation             Guides** assist project staff in the technical details of implementing             ITS.**Case             Studies** provide in-depth coverage of ITS applications in specific             projects ITS Topics Addressed in This Series:- Commercial Vehicle Operations
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