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21st Century Operations Using 21st Century Technologies
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Roles of Transportation Management Centers in Incident Management on Managed Lanes

Chapter 5-Case Studies

This chapter evaluates how the best practices related to TMC-based TIM are applied to several existing managed lane facilities in the United States.

The case studies presented in this guidebook provide a level of insight into the combinations of best practices that can be implemented, why some best practices were implemented versus others, and the considerations that go into choosing best practices for implementation.

As part of the research for this guidebook, the operations of eight managed lane facilities in the United States were reviewed. After the information was collected, three of the eight managed lane facilities were chosen for a more in-depth presentation in the guidebook. The eight facilities investigated by the project team included:

  1. Long Island Expressway (I-495) HOV Lanes (Long Island, NY).
  2. I-35W Priced Dynamic Shoulder Lane (PDSL) System (Twin Cities, MN).
  3. I-10 Katy Freeway Managed Lanes (Houston, TX).
  4. I-95 Express Lanes (Miami, FL).
  5. I-93 Contraflow HOV Lane (Boston, MA).
  6. I-15 Express Lanes (San Diego, CA).
  7. I-85 Express Lanes (Atlanta, GA).
  8. I-495 Express Lanes (Fairfax County, VA).

Table 2 presents an overview of the eight managed lane facilities and the TIM best practices employed by each.

Table 2. TIM Best Practices Comparison for Eight Managed Lane Facilities.

Best Practice Long Island Expressway HOV Lanes I-35W Priced Dynamic Shoulder Lane Houston Katy Freeway Managed Lanes Miami I-95 Express Lanes Boston I-93 Contraflow HOV Lane San Diego I-15 Express Lanes Atlanta I-85 Express Lanes Northern Virginia I-495 Express Lanes
Technology and Communications Established protocols related to incident communications yes yes yes yes yes yes yes yes
Data sharing agreements among agencies - detector data, video feeds, usage statistics yes   yes yes   yes yes yes
Interagency Relations and Coordination Interagency agreements established with response agencies yes yes yes yes yes yes yes yes
Interagency agreements established with other transportation agencies     yes yes   yes yes yes
Managed Lane Enforcement Patrols Manual enforcement / moving violations yes yes yes yes yes yes yes yes
Automated enforcement     yes yes     yes yes
Dedicated police patrols yes yes yes yes yes yes yes yes
Dedicated service patrols   yes yes yes yes     yes
TMC Resources Recovery of some TMC operating costs from toll revenue     yes yes     yes yes
Toll revenue fully supports TMC operating costs     yes         yes
TIM Operational Considerations are incorporated into in the Design of Managed Lanes Managed lane control software   yes yes yes   yes yes yes
Managed lane access and separation treatments yes yes yes yes   yes   yes
Planning Processes and Documents related to Managed Lanes TMC operational considerations incorporated into planning processes yes yes yes yes yes yes yes yes
Shared Operations Responsibilities Managed lanes / general purpose lanes operated by different transportation agency or entity     yes       yes yes
Multiple TMCs with TIM jurisdiction on corridor     yes yes     yes yes
Detect and verify incident from TMC yes yes yes yes yes yes yes yes
Incident Response Coordination of incident response from TMC yes yes yes yes yes yes yes yes
Pre-positioned response and recovery vehicles         yes yes    
Dedicated safety service patrols for managed lanes     yes yes yes yes   yes
Management of Vehicle Access During Incidents in Managed Lanes Adjusting vehicle eligibility during incident   yes       yes yes  
Adjusting pricing during incident   yes   yes   yes yes yes
Closing managed lanes remotely from TMC   yes       yes    
Remotely closing access points from TMC   yes yes yes yes yes yes yes
Scene Management and Traffic Control Activities Select location, establish, maintain effective incident scene yes yes yes yes yes yes yes yes
Coordinate interagency response to open access points to scene     yes   yes yes   yes
Adjust or coordinate the adjustment of movable barriers to support needed traffic flow         yes yes    
Open the use of special use lanes such as HOV or shoulder lanes to improve traffic flow around the scene yes yes       yes yes  
System and Corridor Management Strategies and Systems Lane control signals   yes       yes    
Ramp metering yes yes   yes   yes yes  
Traveler information (DMS / HAR / 511) yes yes yes yes yes yes yes yes
Arterial signal timing yes   yes          
Post diversion information on DMS yes yes yes yes yes yes yes yes
Post travel times yes yes yes yes   yes yes  
Expand/relocate motorist assist patrol services yes yes yes yes yes yes yes yes
Clearance and Recovery Coordinate with responders to support any needs for additional resources yes yes yes yes yes yes yes yes

Many of the best practices are currently implemented on managed lane facilities in the United States. Some of the findings from the investigation are as follows:

  • All managed lane facilities have communication protocols established for incident communications and interagency agreements with responder agencies.
  • Interagency agreements between transportation agencies were needed only when managed lanes were operated by a different entity than the general purpose lanes.
    • The most detailed and formal interagency agreement was between the I-495 Express Lane operator and VDOT, as the managed lanes are privately operated.
  • All facilities have some form of dedicated police patrols for the managed lanes and use those resources for manual enforcement and moving violation enforcement.
    • In some cases, the dedicated patrols are solely responsible for the managed lanes, while in other cases, police resources are shared with the general purpose lanes.
    • On priced managed lane facilities, dedicated police resources may require special equipment that utilizes toll tag readers and/or license plate scanners linked to the toll system.
  • Service patrols covered all managed lane facilities, however only a select few had dedicated service patrols for the managed lanes. Facilities with dedicated service patrols were either privately operated, had pre-positioned vehicles such as tow trucks ready to respond to incidents due to tight lane geometry, or were operated by a toll agency with a dedicated fleet of service patrol vehicles used for other facilities in addition to the managed lanes.
  • Most entities that collect tolls used toll revenue to support TIM, but only two entities fully fund their TMC from toll revenue. These entities maintain their own TMC exclusively for the managed lane system (I-495 Express) or for the managed lane system and other toll roads (Houston). Most other agencies use toll revenue to support TMC operations, but the TMC has shared responsibility with other facilities besides tolled roads and managed lanes.
  • Some form of managed lane control software was in use on priced managed lane facilities. All facilities use some form of software for TIM purposes.
  • Managed lane facilities that involved physical construction took operational considerations into account during the design phase.
    • Facilities that were conversions from HOV lanes (I-85), or fit into an existing right-of-way (I-93 Contraflow HOV Lane) have several design considerations for TIM, but since these facilities were designed to minimize capital costs, the TIM related design features are not the ideal features that would be incorporated into a managed lane facility built from scratch.
    • In all cases, the TMC was involved in operational planning for the facilities.
  • When the managed lanes are operated by a different agency as the general purpose lanes, there are likely to be multiple TMCs with jurisdiction over a corridor. One TMC may have primary responsibility for general purpose lanes, and the other for managed lanes.
    • In some cases, multiple agencies are co-located within one TMC, and an agency's staff may be present at multiple TMCs. This is the case in Houston, where the managed lane operator has staff in its own TMC and in TxDOT's TranStar TMC.
  • Managed lanes on longer corridors may have multiple TMCs involved depending on the coverage area of the TMC. The I-95 Express Lanes are covered by separate TMCs in Miami-Dade and Broward Counties, respectively.
  • Only two managed lane facilities rely on pre-positioned response and recovery vehicles. These facilities (I-15 and I-93) utilize physical barriers that cannot easily be breached or crossed by response vehicles, so vehicles are located inside the lanes.
    • Other agencies use dedicated service patrol vehicles for the managed lanes that have a designated "beat", or patrol route within the managed lane network. This method is helpful where there is no shoulder available to pre-position vehicles. These vehicles on a patrol route are valuable sources of information for incident detection and verification. Response vehicles can cross or breach barriers if necessary to reach an incident.
  • Three managed lane facilities adjust eligibility restrictions: I-85 in Atlanta, I-35W in Twin Cities, and I-15 in San Diego. The restriction is implemented in HOT lanes by removing eligibility for toll-paying vehicles to enter and retaining the existing HOV restriction, rather than altering the HOV restriction threshold.
  • All but one agency with priced managed lanes can adjust pricing in response to an incident. The exception is Houston's managed lane facility, which adjusts the variable tolls based on a set time schedule.
  • Lanes can be closed remotely from the TMC on most managed lane facilities by adjusting electronic signs at entrances to the lanes, though compliance is not ensured without police or incident responder assistance. San Diego and Minnesota have designated resources for closing lanes: lane control signals or pop-up devices activated from the TMC.
  • All agencies without any form of physical barrier between the managed and general purpose lanes, in addition to California (using designated access points) specifically cited the ability to open managed lanes or shoulders to general traffic if needed during an incident.
  • Ramp metering is present on most, but not all managed lane corridors.
  • Two managed lane facilities (Long Island and Houston) specified the ability to regulate arterial signal timing on some parallel diversion routes during an incident.
  • All but two agencies have some corridor travel time information posted on DMSs.
  • All TMCs can give traveler information, diversion information, and have the ability to dispatch additional support for the incident scene and the corridor.

The above summary provides an overview of the practices used on a sampling of managed lane facilities throughout the United States. Three of these examples are highlighted in more detail in the following sections: Minnesota's I-35W HOT/PDSL, Houston's Katy Freeway Managed Lanes, and Virginia's I-495 Express Lanes. Each case will be described in detail, and will focus on a certain aspect of TIM from the TMC in a managed lane environment.

5.1 Case Study 1: Minnesota's I-35W HOT/Priced Dynamic Shoulder Lane and ATM System

Minnesota's Department of Transportation (MNDOT) operates a part-time HOT lane facility on I-35W south of downtown Minneapolis. In the northbound direction, the HOT lane is extended into downtown Minneapolis as a "Priced Dynamic Shoulder Lane" (PDSL). This managed lane facility is operated by the state DOT, so there are no interagency coordination needs between transportation agencies. The portion of the corridor where the PDSL is located does not have adequate shoulders, as the left shoulder is used by the PDSL and there is no right shoulder. As a result, MNDOT has deployed state of the art ITS resources on this managed lane facility and in the TMC with use of an Active Traffic Management (ATM) system. The ATM system gives MNDOT enhanced TIM capabilities for adjusting lane use, speed limits, and access to/from the managed lanes from the TMC. These capabilities are generally not found on most other managed lane facilities.

Overview

Access Restriction
HOT (peak), open to general traffic (HOT Lane, off-peak), operates as a shoulder (PDSL, off-peak)

Physical Separation
Painted line/painted buffer

Location
The I-35W Managed Lane System is approximately 18 miles long and runs in both directions between Burnsville to the south and the City of Minneapolis to the north. The southern section of the system includes 15 miles of HOT lanes with one lane in each direction. On the northbound side, the managed lane system is extended an additional 3 miles into downtown Minneapolis through a Priced Dynamic Shoulder Lane (PDSL).

Design Type
HOT Lanes: the HOT lanes are 12-feet wide and have a reaction area on the left varying from 2 to 10-feet separating the lane from the barrier as well as a 2-foot buffer on the right established by a painted double white line where there is no access and a single skip line at access points (see Figure 40).

PDSL
The PDSL section uses the existing shoulder and is generally 12-feet wide with a 2-foot buffer on the left separating it from the barrier. The PDSL is separated on the right from the general purpose lanes by a single yellow pained line. Access to and from the lanes is continuous.

General Purpose Lanes
The right shoulder of the general purpose lanes is generally 12-feet wide but is limited in the PDSL area to about two feet. In areas where the right shoulder is limited there are emergency pull offs about every one half mile.

Cross section of I-35W freeway and PDSL HOT lane. The illustration shows 5 lanes of one-way travel. The left lane is the managed lane, the right four lanes are general purpose lanes. Destination and variable speed limit signage is positioned over the roadway.

Figure 43. Illustration. I-35W PDSL HOT lane.

Vehicle Eligibility
Free access to the managed lanes (HOT and PDSL) is limited to vehicles with 2 or more passengers (HOV 2+), transit and motorcycles. Single occupant vehicles with toll transponders may use the lane for a charge. The cost is variable depending upon congestion levels in the general purpose lanes.

Operations
The Minnesota Department of Transportation (MNDOT) is the owner/operator agency of the system including the tolling element of the system. The HOT lanes typically operate from 6 AM to 10 AM and 3 PM to 7 PM Monday - Friday. The HOT lanes are open to general traffic at all other hours. The PDSL operates from 6 AM to 7 PM Monday - Friday. The PDSL lane is used as a shoulder at all other times. MNDOT can adjust the specific times of operation at its discretion. During periods of heavy traffic, the PDSL is sometimes left open beyond the 7 PM closure time. The PDSL can also operate on weekends depending upon traffic demand. At the request of MNDOT's snow and ice coordinator, the PDSL will be left open during overnight hours to allow vehicle traffic to disperse anti-icing chemicals.

Additional Special Characteristics Affecting TIM

Bus Shoulder Use
Aside from the PDSL area where there is no right shoulder, buses are permitted to use the right shoulder as a travel lane when speeds fall below 35 MPH on the other lanes. When using the shoulder, buses are limited to traveling no more than approximately 15 MPH faster than vehicles in the adjacent travel lane.

Winter Weather and Snow Removal
The Twin Cities area typically receives large amounts of snow accumulation during the winter season. The winter weather is a significant generator of incidents. The increase in lane miles, reduction in shoulder space, and addition of pull offs on the roadway segments with managed lanes all add to the snow removal requirements. Shoulders are no longer available for temporary snow storage in many locations, the added lanes will require an additional plow, and the pull offs require special equipment that can fit and maneuver into and out of the pull offs. Thus, there are significant additional costs for snow removal, as there are many segments where the snow must be blown into dump trucks and transported off the highway.

TIM State of the Practice Related to the Managed Lanes

Operation and Management
MNDOT owns and operates the managed lane system including the tolling element of the system. The system is monitored and managed from the MNDOT TMC in Minneapolis as part of their overall traffic management responsibilities for all state highways in the area. MNDOT contracts out the fiscal/administrative aspects of the toll system. MNDOT has overall responsibility for both toll and traffic operations and can override pricing and/or open managed lanes to general traffic if conditions dictate.

Traffic/Incident Management (Surveillance/Control - Detection/Verification)
The managed lanes are fully equipped with detectors and cameras for traffic monitoring purposes. In addition there are ramp meters controlling access to the overall freeway based on congestion levels. The entire system is also covered by an Active Traffic Management (ATM) system. The ATM includes Intelligent Lane Control Signs (ILCS), which are overhead signs located at about one-half mile spacing which provide speed harmonization, lane control, and electronic tolling information. The ATM provides a number of incident management capabilities including opening/closing lanes and slowing/smoothing traffic speeds.

Traveler Information
A variety of tools are used to notify the public of conditions that may affect the HOT lane, such as incidents, construction, or diversions. These include the DMS and ILCS as well as a 511 system. In addition, MNDOT has a partnership with a local radio station that broadcasts traffic information every 10 minutes, or more often as needed in the event of a large scale incident.

Enforcement
Enforcement on the system is provided by the Minnesota State Patrol. The State Patrol provides resources for routine enforcement and MNDOT contracts with the State Patrol to provide extra enforcement on the system during the HOT lane hours of operation. There is a dedicated pool of officers who undergo special training in the specifics of traffic enforcement and incident management for the managed lane system. Patrol vehicles are equipped with mobile reader devices that allow them to ascertain whether a vehicle has a toll tag.

Response/Scene Management
The State Patrol is responsible for response to incidents on the system. Other emergency response such as fire and EMS are provided by the appropriate local agencies. MNDOT also has motorist assist patrols (FIRST) that patrol the system to provide routine assistance and can respond to incidents and assist with scene management or push vehicles off the travel way. Towing is provided by local area towing companies as requested by the State Patrol under a tow zone system that considers factors such as equipment, hours of operation, response time, and reliability.

Minnesota has Quick Clearance laws in place to support rapid clearance. MNDOT and the State Patrol have a formal Open Roads Policy. In the event of an abandoned vehicle, the FIRST patrols have authority to initiate the tow. The fact that buses may use the right shoulder to expedite their travel increases the importance of quick clearance of incidents affecting the shoulder.

Diversions
Because the HOT and PDSL have shoulders and access to the general purpose lanes diversion is not a special issue from an incident management perspective. In general, standard procedures are followed when an incident occurs in the managed lanes. As indicated previously, MNDOT can direct general purpose traffic into the managed lanes or waive tolls if necessary, but this is rarely done.

Photo of I-35W in Minneapolis. The photo shows 5 lanes of one-way travel. The left lane is the managed lane, the right four lanes are general purpose lanes, an onramp and offramp are positioned on the right side of the roadway. Destination and dynamic message signage is positioned over the roadway.

Figure 44. Photo. ATM system on I-35W in Minneapolis.

Institutional Coordination

TIM
MNDOT has a robust TIM program in cooperation with the State Patrol as well as local responders as appropriate. Elements of the program include routine coordination meetings, joint training, post incident reviews, and planning for special events.

Agreements
As indicated previously, there are two significant agreements affecting incident management of the system:

  • An Open Roads agreement between MNDOT and the State Patrol.
  • A funding agreement with the State Patrol for additional enforcement patrols on the managed lanes.

Resources/Funding
Resources for operating the managed lanes are generally the responsibility of MNDOT and include both traditional funds as well as toll revenues.

Design/Construction/Maintenance Coordination
There is close cooperation among the MNDOT Design, Construction, and Maintenance Offices with regard to the operational considerations of the managed lanes.

Other Issues
MNDOT has a number of research projects underway to improve system operations/management including:

  • Researching how to modify the advisory speed limit during inclement weather; and
  • Researching the extent to which motorists see and react to the message signs.

Summary of TMC Role in Managed Lane TIM

The MNDOT TMC is responsible for managing and monitoring the PDSL HOT lane. The TMC covers the entire system including the general purpose lanes with cameras, ramp meters, and detectors in order to effectively detect incidents. Since the PDSL system and adjacent general purpose lanes are equipped with an ATM system, the TMC has enhanced incident management capabilities such as the ability to remotely open/close lanes and slowing/smoothing traffic speeds with variable speed limits. The ATM also includes ILCS overhead signs, which are used along with DMS, 511 system, and a partnership with a local radio station in order to disseminate incident information to the public.

The TMC dispatches a dedicated pool of officers with special incident management training that can effectively utilize the enhanced TIM tools that are available on this corridor. In addition, MNDOT TMC operates FIRST motorist assist patrols that routinely patrols the PDSL HOT lane to respond to incidents and assist with scene management. Since the shoulders are used by PDSL and buses, quick detection and clearance of incidents is the goal of the MNDOT TMC in operating this corridor. The TMC has the authority to direct general traffic into managed lanes and waive tolls, and it can also direct managed lane traffic into the general purpose lanes, if necessary. Communication of this change can occur using existing ATM and ILCS infrastructure controlled by the TMC.

Findings

MNDOT's extensive use of ATM is unique among the managed lane facilities examined in this project. In the future, it is likely that more facilities using ATM will be constructed to improve TIM and managed lane operations. ATM may be a mitigation strategy for managed lane facilities constructed in a constrained environment where the geometrics are not ideal from a TIM perspective, such as reduced or narrow shoulders. This will help maximize the use of available roadway space while minimizing the disruption from an incident.

5.2 Case Study 2: Houston's Katy Freeway Managed Lanes and Interagency Coordination

The Katy Freeway Managed Lanes are located on I-10 west of Houston, Texas. The facility is operated as a HOT lane facility during peak hours and as an Express Toll Lane facility during other times where all vehicles pay for access. The entire Katy Freeway corridor underwent significant reconstruction when the managed lanes were built, and is now one of the widest freeway corridors in the country. As a result of this reconstruction, the purpose-built Katy Freeway Managed Lanes have nearly ideal geometrics, with full shoulders on both sides adjacent to a flexible post barrier separating them from the general purpose lanes.

Of interest to planners about the Katy Freeway Managed Lanes is the shared operating responsibility for the corridor. The managed lanes are operated by the Harris County Toll Road Authority (HCTRA), while the general purpose lanes and frontage roads are operated by the Texas DOT (TxDOT). HCTRA operates tolled facilities in and around Houston, while TxDOT is the primary operator of freeways within the region. Each agency operates its own TMC. HCTRA's TMC covers all of its tolled facilities in the region. TxDOT is the lead agency at the TranStar TMC, which co-locates many of the transportation providers in the Houston area under one roof. Included as part of the TranStar TMC are: TxDOT, Harris County, HCTRA, the City of Houston, and the Houston area's transit agency, Metro. In addition to transportation officials, public safety officials are located at the TranStar TMC, which has an emergency management function in addition to a transportation management function. As a result of HCTRA's participation in TranStar, the agency has staff at two different TMC's in the Houston area. Their TranStar presence will enhance their ability to coordinate with other transportation agencies during a major incident, while minor incidents only affecting the managed lanes can be handled from their own TMC. This arrangement actually requires some intra-agency coordination between its TMC staff located in the two different TMCs.

Overview

Access Restriction
HOT (peak hours), Tolled (non-peak hours)

Physical Separation
Plastic "candlestick" post barrier with full shoulders on both sides

Location
The I-10 Express Lanes extend 12 miles in both directions in the center of Interstate 10 in Houston, Texas.

Design Type
There are two 12-foot wide lanes in each direction, separated directionally by a concrete barrier. The express lanes are separated from the general purpose lanes by a plastic post barrier with 12-foot wide shoulders on both sides of the post barrier (see Figure 42). Direct access to/from the express lanes is provided at each end as well as through slip ramp type openings in the channelization at 3 intermediate points. In addition, there is direct access provided from a Park and Ride lot as well as a transit center. There are three toll gantries located within the system between access/egress points that serve as designator lanes to sort HOV users from toll tag users.

Photo of I-10 Katy Freeway with managed lanes with plastic post barriers and full shoulders on either side.

Figure 45. Photo. I-10 Katy Freeway managed lanes with plastic post barrier and full shoulders on either side.

Vehicle Eligibility
Free access to the express lanes is limited to peak hours for vehicles with 2 or more passengers (HOV 2+), motorcycles and exempt vehicles such as metro buses and police. Single occupant vehicles with tags are allowed anytime at a toll price that changes based on time of day. Eligible vehicles must also pay the posted toll price during non-peak hours.

Operations
The Harris County Toll Road Authority (HCTRA) is responsible for the operation of the express lanes including all traffic operations and toll operations. TxDOT is responsible for the operation of the general purpose lanes. The system operates 24/7. Designated peak hours are 5 AM to 11 AM and 2 PM to 8 PM, Monday through Friday.

Additional Special Characteristics Affecting TIM

Toll Gantries
Traffic must sort into one of two lanes at the toll gantries - one lane for HOV-eligible traffic and one for single occupant vehicles with toll transponders. The gantry locations provide an area where enforcement vehicles can park to observe entering vehicles.

Plastic Post "Candlestick" Barrier
The posts can be removed to facilitate diversion to/from the express lanes. They are also flexible enough that vehicles from the general purpose lanes can physically drive over them if necessary to divert traffic in the event of an incident.

Enforcement/Incident Scene Management
Two adjacent 12-foot shoulders, one on each side of the plastic post barrier, provide ample space for enforcement and incident management activities.

Photo of the signage above the Katy managed lanes (or Katy Tollway). Various signs designate HOT operation times during peak hours and ETL at other times, and have a maximum possible toll.

Figure 46. Photo. The Katy managed lanes (or Katy Tollway) operate as HOT during peak hours and ETL at other times, and have a maximum possible toll.

Concurrent Operators
The fact that two separate agencies operate lanes within the system provides special challenges related to traffic management and enforcement coordination, as both agencies need to be involved during any incident where diversion is involved.

TIM State of the Practice Related to the Managed Lanes

Operation and Management
The Harris County Toll Road Authority (HCTRA) is responsible for the operation of the express lanes including all traffic operations and toll operations. TxDOT is responsible for the operation of the general purpose lanes. The Harris County Police provide for enforcement on the express lanes. HCTRA monitors and manages the express lanes from their own 24/7 TMC/Incident Management Center which includes a robust dispatch system. TxDOT monitors and manages the general purpose lanes from the Houston TranStar TMC.

Traffic/Incident Management (Surveillance/Control - Detection/Verification)
The entire system is equipped with a traffic monitoring and management system including cameras and DMS as well as message signs at the designator lane toll gantries. There are two sets of cameras on the system, one for the express lanes/HCTRA and one for the general purpose lanes/TxDOT. Cameras, detector information and DMS messages and control are coordinated to provide seamless operation.

Traveler Information
A variety of tools are used to notify the public of conditions that affect the express lanes, such as incidents, construction, or diversions. These include the DMS as well as a 511 system. As indicated previously, HCTRA shares detector and speed information with the Houston TranStar TMC, and TranStar merges the information and acts as the single source for regional traveler information.

Enforcement
The Harris County Police provide enforcement on the express lanes. There are 13 patrols dedicated to enforcement on the express lanes. The enforcement costs are treated as part of the overall system operations costs and hence come from the toll revenues. In general, the City of Houston Police Department provides for enforcement on the general purpose lanes. The police have mobile data terminals in their vehicles that allow them to enforce violations related to toll tag accounts. The toll gantries provide police with safe locations for parking to perform enforcement activities.

Response/Scene Management
The Harris County Police provide incident response on the express lanes. In general, the City of Houston Police Department provides incident response on the general purpose lanes. The City of Houston provides fire and EMS response on both systems. The HCTRA is able to dispatch any of these resources from their TMC. The HCTRA has four dedicated motorist assist patrols that monitor the express lanes - two for each direction. These patrols support incident response and scene management. Their resources and capabilities include response vehicles with message boards, towing, and hazardous material spill kits. The Harris County Police are aware of the impact that incidents in the general purpose lane can have on the express lanes. They are often the first enforcement vehicles on the scene for general purpose lane incidents and will get involved to initiate and/or supplement response there. Texas has "Steer It/Clear It" and "Move Over" laws to support quick and safe incident management. The HCTRA and Harris County Police have formal quick removal policies and can respond within 5 minutes and clear lanes within 10 to 15 minutes for normal incidents.

Diversions
HCTRA and Harris County Police have the authority to divert traffic from the general purpose lanes into the managed lanes and waive tolls. The frequent entry and exit points on the express lanes as well as quick incident response and wide shoulders make the need for diversion from the managed lanes a rare occurrence. In the event of a major closure the police will not only perform traffic control on the freeway but will also place enforcement personnel at the traffic signals at the frontage roads/arterials.

Institutional Coordination

TIM
HCTRA has a robust TIM program in cooperation with the Harris County Police as well as local responders as appropriate. Elements of the program include routine coordination meetings, joint training, post incident reviews, and planning for special events.

Inter-agency Coordination/Agreements
HCTRA, TxDOT and Metro have a formal "tri-party" agreement that covers interagency coordination related to the express lanes. In general, the parties defer to HCTRA to operate and manage the lanes on a daily basis. The three agencies coordinate more frequently if there are changes to the system or operations that are being considered. In addition, the Harris County Police and HCTRA have entered into an agreement with a local wrecker service to ensure quick response, standard rates and equipment capability.

Resources/Funding
In general, resources are provided by HCTRA and Harris County Police and operations are funded from the toll revenues.

Design/Construction/Maintenance Coordination
There is close cooperation among these offices due to internal procedures and as provided by the tri-party agreement.

Other Issues
These issues were also identified:

  • Future systems should be designed such that all HOV/tag type enforcement can be done in entrance/exit areas where speeds are low. It is very difficult to conduct this enforcement at highway speeds.
  • The use of plastic posts as the express lane separator has both advantages and disadvantages. A key advantage is that the barrier can be temporarily removed or driven over to provide emergency access or diversion. A disadvantage is that lack of a strong physical separation can allow errant vehicles to encroach into adjacent lanes.

Summary of TMC Role in Managed Lane TIM

There are two 24/7 TMCs involved in incident management on the facility; the HCTRA TMC and the Houston TranStar TMC. The two TMCs are located separately. The HCTRA TMC is responsible for monitoring and managing the express lanes, whereas the Houston TranStar TMC is responsible for monitoring and managing the general purpose lanes. The two TMCs operate the whole system as a seamless facility, allowing both to coordinate operations and response during any incident.

The HCTRA TMC is staffed and operated by HCTRA personnel. It focuses on incident management on the express lanes. The Houston TranStar TMC focuses on multiagency operations and management of the region's transportation system. TranStar is a partnership among the principal transportation and emergency management agencies in Harris County, including:

  • Texas Department of Transportation (TxDOT).
  • Metropolitan Transit Authority of Harris County (Metro).
  • Harris County, including:
    • Traffic & Transportation Group.
    • Harris County Toll Road Authority.
    • Office of Homeland Security & Emergency Management.
  • The City of Houston.

The two TMCs coordinate TIM activities related to the Katy Freeway. Their roles include:

  • Monitoring all lanes for operational status and incidents.
  • Operation of ITS detection, DMS, and CCTV devices.
  • Dispatch of motorist assist and incident response units for their respective operational responsibilities.
  • Dispatch and/or coordination with enforcement and emergency responders.
  • Authority to divert traffic during incidents between the express and general purpose lanes.
  • Control of access to the express lanes to manage traffic entry volumes during incidents.
  • Incident management coordination, as well as with operational partners such as Metro and the City of Houston.
  • Sharing of traffic detection information and CCTV/DMS devices through the TranStar TMC to provide for optimum system monitoring and management during incidents.
  • Distribution of incident-related traffic condition traveler information. HCTRA distributes information locally via DMS while TranStar merges information and distributes it regionally to the public and media.
  • Multiagency TIM related operational agreements including the HCTRA/Harris County Police Quick Clearance policy as well as the HCTRA/TxDOT/Metro agreement governing express lane operations.
  • Multiagency TIM program implementation including inter-agency training and debriefings.

The existence of both the HCTRA TMC and TranStar TMC to provide and coordinate focused local managed lane incident management activities, as well as to integrate response and traveler information on a regional level, provides a unique and powerful tool for effective TIM on the Katy Freeway corridor.

Findings

The Katy Freeway Managed Lanes have very strong interagency coordination as one of their key operating strategies. As a result, the Katy Freeway corridor operates as a seamless transportation entity, despite two public agencies having jurisdiction over different parts of the same roadway cross section.

Each entity has procedures for responding to an incident on their portion of the roadway, and there are designated procedures in place for incidents that affect both operators. Each side understands their role and responsibilities prior to the occurrence of an incident, so that any incidents can be resolved as quickly as possible. The interagency arrangements used on the Katy Freeway corridor which allow co-location of some staff resources at one TMC are ideal for facilitation of interagency coordination, provided both agencies are on board and willing to very closely coordinate on a day-to-day basis.

5.3 Case Study 3: Fairfax County, Virginia's I-495 Express Lanes and Private Sector Operators

The I-495 Express Lanes in Fairfax County, Virginia are operated by the private firm Capital Beltway Express (CBE). This firm is a joint venture between a construction firm and a publicly traded firm that operates toll facilities in the United States and abroad. The private ownership of the I-495 Express Lanes introduces some additional complexities into the operation and TIM processes.

Photo of I-495 Express Lanes on the Capital Beltway in Fairfax County, VA, near Washington, DC. the two left-hand managed lanes feature a plastic post barrier and overhead variable message signs.

Figure 47. Photo. I-495 Express Lanes on the Capital Beltway in Fairfax County, VA, near Washington, DC.

CBE entered into a very comprehensive operating agreement with the Virginia DOT (VDOT) related to operation of the I-495 corridor. Each agency's roles and procedures are very clearly spelled out in the form of an operating procedures manual which covers a wide variety of potential scenarios. The scenarios contain specific thresholds for when a procedure is to be implemented. For example, some procedures are related to the issuance of an emergency declaration by the state government.

Capital Beltway Express operates its own TMC, called the HOT Operations Center (HOT-OC). This TMC has direct data links to VDOT's Smart Traffic Center for the Northern Virginia area, and it is via links that incident data and other ITS data is shared. A specified format is used for communication of incident information, and a protocol is in effect for notification from one agency to the other when an incident on one agency's facility is detected by the other. A specified arrangement for cost-sharing and which agency takes the lead for specific incident management are also included as part of the agreement.

Overview

Access Restriction
HOT

Physical Separation
Express lanes are separated from regular lanes by white flexible posts and a 4-foot painted buffer.

Location
The I-495 Express Lanes extend 14 miles along the Capital Beltway between the Springfield Interchange and just north of the Dulles Toll Road in Fairfax County, Virginia.

Design Type
There are 4 high-occupancy toll (HOT) lanes; 2 lanes in each direction (see Figure 45). The express lanes have left shoulders on each side.

Vehicle access is provided at 11 entry/exit points to and from other highways and major side routes. There is no access between the HOT lanes and the general purpose lanes except at the end points.

Vehicle Eligibility
Free access to the express lanes is allowed for vehicles with 3 or more passengers (HOV 3+) using E-ZPass Flex transponders. In addition, motorcycles, transit buses, and emergency vehicles can utilize the express lanes for free. Vehicles carrying 1 or 2 people have to pay a toll to ride in the express lanes. The tolling is dynamic based on the distance traveled and traffic congestion conditions in order to keep the express lanes congestion-free. There are 8 toll gantries in each direction, and tolls are collected electronically using E-ZPass/E-ZPass Flex transponders.

Photo of the I-495 Express Lanes separated from the publicly owned and heavily congested general purpose lanes by a 4 foot buffer with a plastic post barrier. In both directions of travel, vehicle congestion is far greater in the general purpose lanes.

Figure 48. Photo. The I-495 Express Lanes are operated by a private firm and are separated from the publicly owned and heavily congested general purpose lanes by a 4 foot buffer with a plastic post barrier.

Operations
Capital Beltway Express (CBE) is a private firm responsible for the traffic management and operations of the express lanes from their HOT Operations Center (HOT-OC). The HOT-OC operates 24/7. On the other hand, the Virginia DOT is responsible for the operations of the general purpose lanes, and has their own ITS assets located in their TMC. The Virginia State Police (VSP) provides for enforcement for HOV 3+ on the express lanes.

TIM State of the Practice Related to the Express Lanes

Operation and Management
Regardless of the incident location (express or general purpose lanes), immediately following incident identification, the identifying agency shall notify 911 emergency dispatch. For incidents on the express lanes that do not impact the general purpose lanes, CBE takes responsibility for dispatching its Safety Service Patrol and clearing the incident, as well as providing incident data to VDOT. For incidents on the general purpose lanes only, VDOT takes responsibility for dispatching its Safety Service Patrol and clearing the incident regardless of where it started. For those incidents that affect both express and general purpose lanes, VDOT oversees the response and coordinates with the emergency first responders.

Response to Unplanned Incidents
In addition, for all unplanned incidents related to the express lanes, CBE shall transmit the following data to VDOT using the data connection between their respective TMCs:

  • Location of the incident (by mile marker and nearest interchange).
  • Lane(s) impacted.
  • Severity of incident.
  • Number of vehicles involved.
  • Number of disabled vehicles.
  • Whether there are any injuries.
  • Whether hazardous materials are involved.
  • Estimated time for response to incident.
  • Estimated duration of incident.
  • Updates regarding the status of incident.


Chart/Graphic showing that all reported incidents by from VDOT or CBE should contact 911 and then alert Safety Service Patrol.

Figure 49. Chart. Response to unplanned incidents along I-495.

Traffic/Incident Management (Surveillance/Control-Detection/Verification)
In addition to the pan-tilt-zoom (PTZ) CCTV cameras, the entire system is equipped with automated incident detection cameras that are capable of detecting lane blocking events, wrong way vehicles, false alarms, and medial/opposite direction locations. Moreover, it is equipped with the DYNAC GIS-based incident response system with multi-cast digital video to quickly and more accurately pinpoint incidents. Both CBE and VDOT provide each other access to the streaming videos and ITS data collected from the express and general purpose lanes, respectively.

Traveler Information
A variety of tools are used to notify the public of conditions that affect the express lanes, such as incidents, construction, diversions. These include the dynamic message signs (DMS) at each entrance, 495 Express website, VA511 website, and mobile apps. Typically, CBE and VDOT's communications teams are engaged only for those incidents categorized as "Level 3", which is the most severe type of on-road incidents. For incidents in the express lanes or express access ramps, CBE manages the crisis communications. For incidents in the general purpose lanes or ramps, VDOT manages crisis communications. For incidents blocking both general purpose and express lanes, VDOT oversees a coordinated communications response with CBE's assistance.

Diversions
Diversions can be performed using the designated access points in the system. In addition, as part of any declared emergency evacuation routing, CBE will follow VDOT's directives delivered by authorized representatives with respect to suspension of tolling, allowing VDOT to take control of the express lanes, diversion of traffic into the express lanes, controlling the CBE's DMS messaging for declared emergencies, and compliance with Virginia Department of Emergency Management's evacuation plans.

Institutional Coordination

Interagency Coordination/Agreements

As mentioned earlier, CBE (via its HOT-OC) and VDOT (via its Northern Virginia TOC) operate express and general purpose lanes, respectively. Since CBE is a private entity and VDOT a public sector transportation agency, coordination between VDOT and the private operators of the managed lanes is unique. Both agencies have formal agreements in place to facilitate coordination between the public and private sector, including a Joint Operating and Maintenance Protocols document. The Joint Operating and Maintenance Protocols address a wide variety of coordination issues including:

  • An organizational structure and protocol for ongoing coordination through a management committee for non-real time coordination, and via contact between VDOT's Transportation Operations Center and CBE's Traffic Control Supervisor for real time coordination.
  • VDOT's right to temporarily override DMS messages during a declared emergency or a significant incident involving fatalities.
  • Situations in which each entity will implement a Unified Command Team to coordinate response to severe incidents.
  • VDOT's ability to suspend tolling in the event the HOT lanes are designated for use as emergency evacuation routes or as an alternate route for diversion from other state highways or the general purpose lanes in the event of an emergency or significant incident involving fatalities. VDOT will have no financial liability for this action.

The operation system protocols require advance notifications from CBE to VDOT for any planned or unplanned maintenance/outages on the express lanes in relation to traffic detection, communications, traffic signals and intersection control, power and lighting systems. VDOT is also required to notify CBE with similar activities on the general purpose lanes.

Summary of TMC Role in Managed Lane TIM

The I-495 Express Lanes in Virginia are unique in that the managed lanes are operated by the private sector and run immediately adjacent to publicly operated general purpose lanes. This provides unique challenges to coordination and operation of the roadway corridor, since each entity has different operating strategies, resources, and equipment. A detailed agreement by both the private and public sector entities must be in place to ensure that each operator will keep the other informed, and that the transportation network operates seamlessly from the perspective of the public.

The HOT Operations Center (HOT-OC) of the Capital Beltway Express (CBE) is responsible for management and operations of the express lanes, while VDOT's Northern Virginia TOC is responsible for operation and management of the general purpose lanes. The CBE HOT-OC has CCTV and Automated Incident Detection cameras covering the whole system as well as DYNAC GIS-based incident response system to quickly and more accurately pinpoint incidents. CBE HOT-OC also has dedicated safety service patrols that are responsible for clearing incidents on the express lanes in coordination with Virginia State Police. CBE and VDOT have formal agreements and joint operation and maintenance protocols that facilitate the response and management of incidents on both sets of lanes.

The information in the agreement focuses on which entity is responsible for TIM and specific communication protocols for when one operator detects an incident in the other operator's lanes. Diversions between the express lanes and general purpose lanes are possible using existing ramp infrastructure. VDOT has ultimate responsibility and the ability to control ITS assets of both entities for large incidents that affect both the general purpose and managed lanes, as well as during declared emergencies.

Findings

Although there are few privately operated managed lane facilities in the United States, many more are expected in the future as transportation agencies discover the benefits of public-private partnerships. Careful negotiation of operating agreements is critical to the success of these facilities, and will ensure that the unique needs of the public sector agency and private entity are met during both normal operations and incidents. The I-495 Express Lane model of prior interagency planning resulting in a comprehensive operating procedures document is one that can be followed by other agencies desiring to establish successful public-private partnerships.

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