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Federal-Aid Highway Program Guidance on High Occupancy Vehicle (HOV) Facility Lanes
September 2016

Chapter IV Implementation

Establishing an HOV facility requires implementation of specific occupancy requirements, and involves various activities and the coordination of a variety of agencies and groups. Taking a comprehensive and systematic approach to the implementation process will help ensure that the HOV facility is constructed, designed, and operated in a safe and efficient manner. For example, the development of a concept of operations and application of a systems engineering process will assist States in addressing system lifecycle costs from concept thru design, installation, testing, operations, and maintenance. Such coordination also will help identify applicable regulatory requirements and any needed approvals, such as design approval for change of Interstate System access and Intelligent Transportation System architecture final rule compliance. In this section the terms "States" and "public authorities" are used interchangeably to identify the authority that manages the lane because in some cases State legislation affects the management of HOV lanes.

Examples of significant operational changes:

  • A significant change to the minimum occupancy requirement (e.g., a change from 2+ to 3+ or higher);
  • Switching from 24-hour HOV lane operation to operation during only a portion of the day or week; or
  • Allowing any exceptions to vehicle minimum occupancy requirement permitted in 23 U.S.C. 166(b), such as HOT vehicles or low emission and energy-efficient vehicles.

In the course of managing HOV facilities, some minor or significant physical or operational modifications may be needed to meet changing conditions. States are encouraged to work with their local FHWA Division Office if significant operational changes, relevant to the annual certification or original project commitments, are proposed. In this way, agencies can ensure that all Federal statutory requirements and original project commitments are met.

Original project commitments and/or the source of Federal funds used for implementation of the HOV lanes may preclude certain changes to such facilities. For example, based upon restrictions or requirements associated with the use of Federal-aid highway funds, States are not authorized to convert an HOV lane to a general-purpose lane if funds to construct the facility were made available under the Congestion Mitigation and Air Quality Improvement or the Interstate Maintenance Programs. Other Federal funding sources may have similar requirements that limit the ability of operating agencies to change HOV/HOT lanes to general-purpose lanes or to establish a minimum occupancy requirement of four or more for an HOV facility where practically no or minimal HOV users exist.

Agencies that own and operate HOV lanes are encouraged to involve the FHWA Division Office in the development of programs and initiatives to monitor how well the lanes are functioning, to assess their effectiveness with regard to improving the efficient of travel, to identify new strategies to improve performance, or to analyze the impacts of any significant changes on either the transportation system (including how it is operated), regional HOV system, or both.

Performance Monitoring, Evaluating, and Reporting Program

Establishing a program to a monitor and evaluate program for the performance of an HOV-only lane can help determine if the facility is meeting its goals and objectives. The results of the performance evaluation provide the basis for making revisions to improve the operation of the HOV system or specific lanes. Note: annual lane certification is mandatory under 23 U.S.C. 166(d)(1) when the public authority with jurisdiction over the HOV facility allows exempted vehicles to access the HOV lane; it is not mandatory for HOV-only facilities, but there is nothing wrong with applying the former precepts against the latter conditions, if only for a qualitative test.

Evaluating HOV lanes is similar to evaluating other highway facilities where safety, vehicle volumes, and level of service are examined. However, HOV evaluations also examine facility impacts on the movement of people (how many people, as opposed to how many vehicles, use the lane); modal shifts (how many people changed their travel behavior to take advantage of the HOV lane); reliability; and travel-time savings. These are all important indicators of HOV lane performance.

The process for assessing possible HOV operating strategies should be similar to the one used to plan a project and should emerge from an established monitoring program. Information on vehicle and passenger volumes, travel speeds, travel-time savings, violation rates, and crashes should form the basis of an ongoing monitoring and evaluation program. This information can be used to identify possible problems and potential changes in the operation of an HOV facility.

Technical guidance and recommended practices on performance monitoring and evaluation of HOV systems can be found in the National Cooperative Highway Research Program Report 414: "HOV Systems Manual." For additional resources, refer to Chapter VI in this Program Guidance or visit the FHWA HOV Program Web site at

Example: Determining Operational Performance

The Situation

A 20-mile HOV facility (that allows low emission and energy-efficient SOVs) has a speed limit of 55 MPH and a one-mile long bottleneck with an average operating speed of 20 MPH and a 50 MPH average operating speed for the remainder of the facility. Does the performance of this facility meet the Federal requirement (under 23 U.S.C. 166(d)(2)) of a 45 MPH average operating speed?

Although the average operating speed for the entire facility in this example is 46.5 MPH, the facility may be considered degraded based on the predominant usage pattern and the impact of delays at the bottleneck.

If the predominant usage pattern consists of relatively short trips (5 or 10 miles) that pass through the bottleneck location, the average operating speed for these trips will be well under 45 MPH and the facility would be considered degraded.

If the predominant usage pattern consists of longer trips that traverse most or all of the facility, including the bottleneck, the facility would not be considered degraded simply because of the relatively short bottleneck.

For "HOV+" facilities (i.e., ones that combine HOV with SOVs or low emission or energy-efficient vehicles) the minimum average operating speed is defined in section 166(d)(2)(A) as 45 MPH with a speed limit of 50 MPH or greater, and not more than 10 MPH below the speed limit for a facility with a speed limit of less than 50 MPH. This standard could be considered a de facto test for HOV-only facilities but is not mandated as such. Section 166(d)(2)(B) further provides that an HOV facility is considered degraded if it fails to maintain a minimum average operating speed 90 percent of the time over a consecutive 180-day period during morning or evening weekday peak hour periods (or both for a reversible facility). It is noted that a facility may have one or more locations where this operating speed is routinely not met, but still be able to maintain the minimum average operating speed over the length of the entire facility or segment. The impact of bottleneck delay on an HOV facility is dependent on the length of the bottleneck and the predominant usage pattern of the HOV facility. A minor bottleneck on a long facility may not be a problem, whereas a bottleneck on a short facility or on a critical segment could have a greater impact and lead to a degraded condition. See sidebar to left for example.

A minimum average operating speed can ideally be obtained by collecting data at multiple locations. Data collection points can either be spaced uniformly at equal distance apart from one another or at strategic locations. The monitoring should be conducted, at a minimum, during peak periods. A State should evaluate this regular monitoring information to develop an understanding of the operating and usage characteristics of the facility in order to assess whether overall incentives to use the HOV facility are adversely impacted by the bottleneck location(s).

The FHWA does not require use of a specific procedure or methodology for States to use in determining if the operational performance of an HOV facility is degraded. This is because each HOV facility has different characteristics and each State agency has different resources to collect and analyze data. The appropriate frequency of data collection should be determined based on the type of HOV facility, number and location of entrance and exit points, traffic patterns, etc. States are encouraged to create monthly reports as a means to continually monitor and evaluate the HOV facilities. A public authority or State DOT is encouraged to work with the local FHWA Division Office to develop a detailed performance-monitoring program that outlines the methodology it will use to determine whether the particular HOV facility meets applicable Federal operational performance requirements.

Examples of Performance Monitoring Programs:

  • I-394 MnPass HOT Lanes
  • CA Statewide Hybrid Vehicle Program
  • Long Island Expressway Clean Pass Pilot Program
  • Washington State HOV System HERO Program

If the public authority allows HOT or low emission and energy-efficient vehicles to use an HOV lane, and the lane becomes degraded, section 166(d)(1)(C) requires the State to limit or discontinue the use of the lane by the number of HOT vehicles and/or low emission and energy-efficient vehicles necessary to bring the facility back to compliance or to take other actions that will quickly bring the operational performance up to the Federal standard. Data showing that the HOT and low emission and energy-efficient vehicles caused the degradation is not required. The State has discretion in deciding which vehicles to limit or discontinue as well as the manner and means through which to do it. For example, the State may utilize a variety of options for improving the operation of its HOV facilities, such as improving enforcement, increasing the fuel economy percentages, increasing the occupancy requirements, establishing tolls, or varying the tolls by time of day or actual traffic conditions. The State's remedial plan, including its choice of options, is subject to an FHWA determination whether the plan will make significant progress toward bringing the facility into compliance with the minimum average operating speed performance standard.

HOV Facility Management, Operation, and Monitoring (Arterials) - 23 U.S.C. 166(d)

Picture showing a generic highway patrol vehicle.
Picture showing a generic highway patrol vehicle.

Arterial street HOV facilities are found within a wide range of settings and environments in an urban area, for example, in downtown/central business districts, suburban activity centers, neighborhood commercial areas, and major commuter travel corridors. Arterial streets are typically designed to operate at travel speeds of 25 to 50 MPH. Hence, the minimum average operating speed must not be more than 10 MPH below the speed limit for an arterial street facility, in accordance to 23 U.S.C. 166(d)(2)(A)(ii).

The operating environment for an HOV facility on an arterial street is much different from the operating environment on freeways. Examples of considerations used to determine the average operating speed for arterial facilities are: delays due to signalized intersections, driveway access, turning movements, on-street parking, and buses stopping to drop off and pick up passengers, etc. A State may derive an average operating speed based on the average travel time using these considerations.

Enforcement Program

Enforcement is critical to the successful operation of an HOV facility. The role of an HOV enforcement program is to protect the integrity of the facility by deterring possible violators and promote the safe and efficient use of the HOV lanes. If a State allows HOT or low emission and energy-efficient vehicles to use an HOV lane, the operating agency must establish, manage, and support an enforcement program that ensures the facility is being operated in accordance with the requirements of section 166, including the performance standards stated in 23 U.S.C. 166(d).

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