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Federal-Aid Highway Program Guidance on High Occupancy Vehicle (HOV) Lanes
November 2012

Chapter III Overview of Legislation

Sections 1512 ("Tolling") and 1514 ("HOV Facilities") are the two sections of MAP-21 that address HOT and HOV lanes, respectively. One other section that has some tangential relationship to this subject is Section 1513 ("Miscellaneous Parking Amendments") which alludes to the accommodation of Federal-aid funding to acquire qualifying lands, and pay for qualifying projects that locate and build electric vehicle charging stations or natural gas vehicle refueling stations. The MAP-21 amendments that are relevant to this issue are 23 U.S.C. Section 137(f) and (g), Section 142 (a), and Section 205 (d), which allow for said charging station-Federal reimbursement for "fringe parking"areas, "public transportation-related" areas, and "forest development roads and trail" areas, respectively. The reader is directed to those sections for exact language and guidance.

Specific to HOV/T lanes, what MAP-21 does is to amend portions of U.S. Code Title 23, which outlines the roles of highways in the United States. In the case of 1512, it amends Section 129 ("Toll Roads, Bridges, Tunnels and Ferries") whereas, 1514 amends Section 166 ("HOV Facilities").

Section 1512 of MAP-21 amends Section 129(a) of 23 U.S.C. to define options for operating HOV facilities. Sections 129(b) and 129(c) were not amended; regardless, both of those sections deal with ferries and ferry terminal facilities, and are less relevant to this document hereafter. States have flexibility with which to manage the use of their HOV-lane capacity by allowing some vehicles to travel exempt from the minimum vehicle occupancy requirements. For example, HOT or qualified low emission and energy-efficient vehicles (such as hybrids) SOVs/LOVs may use HOV lanes. The remainder of this chapter presents an overview of the key features in the legislation. Subsequent chapters discuss the legislative requirements for implementing the key provisions. A full recitation of as-amended Section 166 of 23 U.S.C. is provided in Appendix A. A full recitation of as-amended Section 129 of 23 U.S.C. is provided in Appendix B.

Occupancy Requirement - 23 U.S.C. 166 (a)

The 2+ vehicle occupancy requirement remains unchanged from SAFETY-LU. A State agency that has jurisdiction over the operation of an HOV facility continues to have the authority to establish the occupancy requirements of vehicles operating on the facility.

Tolled Vehicles

Title 23 U.S.C. 166 allows States to toll vehicles for access to HOV lanes only when (1) they do not meet the established occupancy requirements of the lane (e.g., HOV-2 on an HOV-3 facility) or (2) they are ILEV or low emission and energy-efficient vehicles. HOT vehicles must be tolled; the tolling of low emission and energy-efficient vehicles and SOV public transportation vehicles is optional. Motorcycles and bicycles, if allowed, may not be tolled.

Allowable Exceptions and Tolls - 23 U.S.C. 166(b)

MAP-21 gives operating agencies responsible for HOV facilities the option of allowing three specific vehicle classes to travel on such facilities exempt from the posted vehicle occupancy requirements: (1) public transportation vehicles (i.e., out-of-service); (2) HOT vehicles; and (3) low emission and energy-efficient vehicles (such as hybrids). In addition, MAP-21 provides that States may restrict motorcycle and/or bicycle operations on HOV facilities "if the agency certifies . . that such use would create a safety hazard." Generally speaking, most all states have restricted bicycles from HOV/T lanes and some have restricted motorcycles. Check with your state's specific HOV/T rules. Each of the other vehicle types are discussed in the following sections of this chapter and a summary of the requirements for these exceptions to minimum occupancy requirements is provided in Appendix B.

High Occupancy Toll Vehicles - 23 U.S.C. 166(b)(4)

A HOT vehicle is any non-exempt vehicle that is charged a toll to use an HOV facility. By default, a HOT vehicle is almost always a SOV, since any vehicle having 2+ persons (or 3+ on some facilities) would qualify as an HOV. Depending on each State's laws, the qualifying HOV may or may not have to have a transponder, etc., to be recognized as such. If a State decides to allow HOT vehicles to use an HOV lane, the State must also (1) establish programs addressing how operators of HOT vehicles can enroll and participate in the toll program; (2) develop, manage, and maintain a system that will automatically collect the toll; and (3) establish policies and procedures to manage the demand of the facility by such vehicles by varying the toll amount and enforcing violations. Further, operational performance must be consistent with Federal requirements.

Inherently low emission vehicles (ILEV) and low emission and energy-efficient vehicles - 23 U.S.C. 166(b)(5)

This section extends the existing exemption for ILEVs and energy-efficient vehicles. Until September 30, 2017, States may allow ILEVs and vehicles certified and labeled as low emission and energy-efficient vehicles (including alternative fuel vehicles) that do not meet the established occupancy requirements to use HOV facilities so long as the State establishes procedures to enforce the restrictions on the use of the facility by these vehicles. These vehicles may be tolled, but, unlike HOT vehicles, the toll is not required. If a toll is charged, it must be less than or equal to that which is charged to qualifying vehicles under paragraph (4). After September 30, 2017, the States must discontinue use of ILEVs, et al, in their HOV lanes unless Congress either extends MAP-21, or supersedes it with a new highway funding bill.

The Clean Air Act Amendments created the ILEV program and TEA-21 allowed States to authorize ILEVs to use HOV lanes without meeting the occupancy requirements. The EPA administers the certification, labeling, and other regulatory provisions of the ILEV program and maintains an updated list of certified ILEVs at

According to section 23 U.S.C. 166(f)(3) "Low emission and energy-efficient vehicles" (colloquially "hybrid" vehicles) are defined as those that have been (1) certified by the EPA as meeting the Tier II emissions level established pursuant to section 202(i) of the Clean Air Act for a given make and model year and (2) certified by the EPA as achieving not less than a 50 percent increase in city fuel economy or not less than a 25 percent increase in combined city-highway fuel economy relative to a comparable vehicle that is an internal combustion gasoline fueled vehicle (other than a vehicle that has propulsion energy from on-board hybrid sources). The EPA is responsible to issue the rules that establish the certification and labeling requirements for low emission and energy-efficient vehicles.

The category of low emission and energy-efficient vehicles also includes alternative fuel vehicles. "Alternative fuel vehicles" are vehicles that operate solely on methanol or other alcohols; a mixture of at least 85 percent methanol or other alcohols, natural gas, liquefied petroleum gas, hydrogen, coal derived liquid fuels, fuels derived from biological materials; or electricity.

States are permitted to implement a more stringent definition of low emission and energy-efficient vehicles in order to better manage the performance of their HOV lanes when used by these vehicles. For example, a State may choose to allow only low emission and energy-efficient vehicles that can demonstrate an 85 percent increase in city fuel economy and a 25 percent increase in city-highway fuel economy, or a 45 percent increase in combined city/highway fuel economy and a 50 percent increase in city fuel economy (or increase both percentages) to travel as SOVs/LOVs. States may also implement other requirements to restrict the use of their HOV facilities by low emission and energy-efficient vehicles, such as caps on the number of eligible vehicles or vehicle class or weight restrictions. However, States may not implement other fuel economy based standards, such as a miles-per-gallon standard, because any fuel economy based standard that is not based on the percentages framework provided at 23 U.S.C. 166(f)(3) conflicts with Federal law.

Public Transportation Vehicles (Out-of-Service) - 23 U.S.C. 166(b)(3)

Public transportation vehicles are vehicles that provide designated public transportation, as defined in 42 U.S.C. 12141, or provide public or private primary, secondary or tertiary school transportation. Public transportation vehicles must be owned and operated by a public entity, operated under a contract with a public entity, or operated pursuant to a license by the Secretary or State agency to provide motorbus or school vehicle transportation services to the public. Per Section 166 (b)(3) States may allow public transportation vehicles that do not meet the established occupancy requirement (i.e., public transit vehicles on deadhead trips) to use HOV facilities without charge if the State agencies establish requirements for identifying the vehicles and set procedures for enforcement.

Motorcycles and bicycles - 23 U.S.C. 166(b)(2)

By law, motorcycles and bicycles are allowed to use HOV facilities. However, a State may elect to restrict motorcycle or bicycle (or both) use of an HOV facility due to safety concerns. If a State does decide to exclude motorcycles and/or bicycles, a certification stating that their presence creates a safety hazard must be submitted to the FHWA for approval. Prior to acceptance, the FHWA will publish the request in the Federal Register, providing an opportunity for public comment. After the State has addressed the comments received (if any), FHWA will approve the request. States should submit their certifications to the FHWA Division Office.

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

In general, a State agency that allows vehicles to use an HOV facility under paragraph (4) "HOT vehicles" or (5) "ILEVs, et al" must annually certify that operational performance monitoring programs and enforcement programs are in place to ensure that the performance of the subject facility is not degraded and is operated in accordance with the restrictions and requirements of 23 U.S.C. 166. As part of the certification, the State must document that the performance of the facility is not currently degraded and must further document the actions that will be taken to guarantee that operational performance will not become degraded in the future. If the operation of an HOV facility open to HOT or low emission and energy-efficient vehicles becomes degraded, States must take necessary actions, such as limiting or discontinuing the use of HOV facilities by the subject vehicles or increasing the price paid by non-exempt vehicles for access to HOV lanes.

Facility degradation is defined in Section 166(d)(2) as one that does not meet minimum average operating speed of 45 MPH for 90 percent of the time over a 180-day monitoring period during morning and evening weekday peak hours (or both), in the case of a HOV facility with a speed limit of 50 MPH or greater, or not more than 10 MPH below the speed limit in the case of a facility with a speed limit of less than 50 MPH.

To avoid the need for potential corrective action, States are encouraged to work with their local FHWA Division Office before allowing SOV/LOV, HOT or low emission and energy-efficient vehicles (i.e., hybrid vehicles) to use HOV facilities. More information on the certification requirements can be found in Chapter IV.

Beginning with MAP-21, Sections 166(d)(D) and (E) were adopted. Section (d)(D) prescribes that the State has 180 days following notice of degradation to "bring the facility into compliance with the minimum average operating speed performance standard through changes to operation of the facility, including" (1) increasing the occupancy requirement for HOV lanes; (2) varying the toll charged to vehicles under subsection (b); (3) discontinuing allowing non-HOV vehicles to use the HOV lanes under subsection (b); or, (4) increasing the available capacity of the HOV facility. Section (d)(E) prescribes penalty, such that if the state fails to bring a facility into compliance under (D), then the Secretary shall subject the State to appropriate program sanctions under Section 1.36 of Title 23 (or successor) until the performance is no longer degraded. For the record, that section reads as follows: If the Administrator determines that a State has violated or failed to comply with the Federal laws or the regulations in this part with respect to a project, he may withhold payment to the State of Federal funds on account of such project, withhold approval of further projects in the State, and take such other action that he deems appropriate under the circumstances, until compliance or remedial action has been accomplished by the State to the satisfaction of the Administrator.

Applicability of the National Environmental Policy Act (NEPA)

State agencies with jurisdiction over HOV facilities hold the sole authority to set occupancy requirements and to implement any of the HOV occupancy exceptions under 23 U.S.C. 166(b). There is no discretionary decision or any approval action to be made by the FHWA in these areas, except where a State wishes to exclude motorcycles or bicycles from an HOV lane under 23 U.S.C. 166(b)(2)(B). As such, NEPA does not apply to the States' actions in setting the occupancy requirements or implementing any of the HOV occupancy exceptions, including converting HOV lanes into HOT lanes under 23 U.S.C. 166(b)(4). Only when other factors, such as Federal-aid funding or a need to amend previous commitments, give rise to a FHWA approval must the FHWA perform a NEPA evaluation. States are encouraged to coordinate with the local FHWA Division Office in the early planning phase in determining whether the implementation of any exception, such as the conversion of a HOV lane into a HOT lane, will be part of a Federal-aid project or whether any previous commitments made in prior NEPA decisions or Federal-aid project agreements require any FHWA actions or approvals that would trigger a NEPA review. It should be noted that, even if the project is a "pure" §166 action and may not involve any discretionary Federal action, certain conformity requirements must be met under 40 CFR 93.121 if it is a regionally significant project within an air quality nonattainment or maintenance area. This applies to projects that require adoption or approval by any State, regional, or local agencies that routinely receive title 23 U.S.C. or Federal Transit Laws funds, as defined in 40 CFR 93.101.

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