For nearly 30 years, freeway High Occupancy Vehicle (HOV) lanes have been developed in Los Angeles County as an incentive to encourage people to carpool, vanpool or ride the bus. While it has generally been accepted that HOV lanes have played a significant role in the management of congestion on County freeways, the systematic evaluation and documentation of the success - or limitations - of HOV lanes has been somewhat limited.
The Metro Board of Directors recognized the need to objectively evaluate the performance of the HOV System in Los Angeles County. Metro will use the information gathered in the HOV Performance Program to make more informed decisions regarding future HOV capital investments and changes in operational policy.
The HOV Performance Program builds on existing Caltrans data collection and monitoring efforts to develop a more comprehensive and analytical approach for evaluating HOV system performance. This website will provide you with the latest information regarding Los Angeles County's HOV Performance Program.
The purpose of the HOV system in Los Angeles County is to enhance mobility for all County residents and visitors by providing a variety of transportation options. In Los Angeles County, the HOV system includes freeway HOV lanes, HOV access ramps, park-and-ride lots and transit stations along HOV corridors.
The HOV system gives travelers who carpool, vanpool or ride the bus more reliable travel on freeways. The availability of this more reliable travel provides a strong incentive for even more people to choose to leave their cars at home and travel by carpools, vanpools or buses.
Today, the State of California has 1410 HOV lane miles, representing approximately 2.78% of the state highway system's total lane miles. Over 36% of these HOV facilities (513 lane miles) can be found in Los Angeles County, making it one of the largest HOV systems in the country. 
Historical Development of HOV in Los Angeles County
The first HOV facility in Los Angeles County was opened in 1973 as a bus-only facility known as the El Monte Busway. Operating along the I-10 freeway corridor between El Monte and downtown Los Angeles, the El Monte Busway was opened to carpools of three persons or more in 1976. Recent changes in California state legislation will result in a reduction in the carpool size requirement on the El Monte Busway to two persons or more for times outside of weekday peak periods.
Despite the success of the El Monte Busway project, the further expansion of the Los Angeles County HOV system was limited between 1976 and the early 1990's. During this period, a "Commuter Lane" was added to the SR-91 Freeway as the only new HOV lane project in the County. The SR-91 Commuter Lane, which opened in 1985, provided a eastbound travel lane for carpools of two or more persons.
The Intermodal Surface Transportation Efficiency Act (ISTEA) was enacted in 1991 changing many federal requirements regarding the planning and programming of the transportation infrastructure. ISTEA promoted innovative ways to address transportation system deficiencies and to improve mobility and air quality in major metropolitan areas. HOV was identified in ISTEA as an appropriate transportation solution for addressing these problems.
In 1992, the Los Angeles County Transportation Commission (LACTC), which was one of the predecessor agencies of Metro, adopted the "Carpool Lane Plan" for Los Angeles County. The plan detailed a system of HOV facilities to serve Los Angeles County and established priorities for HOV system development. In 1992, LACTC and Caltrans also signed a Master Cooperative Agreement for the development of the County HOV system, signaling the start of rapid HOV system expansion.
In June 1993, there were 58 lane miles of HOV lanes in Los Angeles County. By the following year, an additional 73 lane miles of HOV lanes had opened on County freeways, including the Century Freeway (I-105) carpool lanes. In 1996, the Harbor Freeway (I-110) Transitway had opened for transit bus, vanpool and carpool users. By June 1997, the Los Angeles County HOV system had reached 269 lane miles. Between June 1997 and January 2010, 244 lane miles of HOV lanes were added to the County HOV system, bringing the total system to 513 lane miles.
Existing HOV System in Los Angeles County
Today, the Los Angeles County HOV system is carrying more people than any other HOV system in the United States, and is one of the few HOV systems in the country that has been able to sustain a growth in carpools.
The Los Angeles County HOV system is part of a larger regional HOV system that serves the five counties of the Los Angeles metropolitan area (Los Angeles, Ventura, Orange, San Bernardino, and Riverside). The Los Angeles metropolitan area HOV system covers over 960 lane miles, representing over 68% of the HOV lane miles in the entire State of California.
The entire County HOV system is open to only HOV traffic, 24 hours a day-seven days a week. With the exception of the El Monte Busway, all Los Angeles County freeway HOV lanes permit carpools with a minimum occupancy of two persons. Changes in California State legislation allow Ultra Low Emission Vehicles (ULEV's) to use HOV facilities throughout the state, regardless of occupancy.
On average, a HOV lane in Los Angeles County accommodates 1,300 vehicles or 3,300 people per hour during peak periods, and the HOV system serves approximately 331,000 vehicle trips or 780,000 person trips per day. 
In addition to the HOV freeway lanes, the system includes freeway-to-freeway HOV direct connector interchange ramps, direct freeway HOV lane to transit terminal bus ramps, park-and-ride lots, freeway to park-and-ride connector ramps, direct freeway HOV lane entrance and exit ramps and freeway ramp meter HOV bypass lanes.
Metro, in cooperation with Caltrans, is in various stages of planning, design and construction for additional HOV facilities for Los Angeles County. The Los Angeles County HOV System Status Map illustrates the status of HOV projects currently programmed by Metro, in addition to the existing HOV system in Los Angeles County.
Currently, there are a total of 513 HOV lane miles completed to date and 132.2 HOV lane miles currently in construction, design or planning on six major corridors. This includes 43.4 HOV lane miles currently in construction or going to construction (I-10, SR-60, the I-405 Design/Build project and the I- 5/SR-14 Direct Connector), 52 HOV lane miles currently in design (I-5 and I-10) and 36.8 HOV lane miles currently in the planning stage (I-5, SR-14 and SR-71). Over the next year, we anticipate opening 22.6 additional HOV lane miles.
 California Department of Transportation, “ Data Integration and Reporting Branch (DIRB) State Highway Mileage and Other Data." November 2009
 Caltrans District 7, " 2008 HOV Annual Report - Executive Summary ", January 2009
- What is HOV?
- What is SOV?
- What are HOV lanes?
- What is the difference between HOV and HOT?
- How do HOV lanes work?
- Sometimes it seems the HOV lanes are empty so does that mean they're not working?
- If I drive alone, why should I support HOV lanes when I can't use them?
- What would happen if HOV lanes were eliminated altogether from places where they exist?
- Where can I find out about ridesharing opportunities?
- Are there other types of HOV facilities besides HOV lanes?
- What do HOV lanes look like?
- What types of HOV lanes are used in the Los Angeles area?
- How many HOV lanes are there in the U.S.?
- Is it legal to restrict publicly-funded highway lanes to HOVs?
- How are HOV lanes enforced?
- What happens to drivers who violate HOV lane rules?
- Why do some HOV lanes allow a minimum of two passengers per vehicle, while others require a minimum of three?
- Do children and infants count as passengers?
- Why are motorcycles allowed in some HOV lanes?
- Are two-seater vehicles allowed to use HOV lanes with three-person requirements?
- Are there any vehicles that are prohibited from using HOV lanes, even with the appropriate number of passengers?
- Are there situations where Single Occupant Vehicles are permitted to use HOV lanes?
- What is the safety record of HOV lanes?
- Do HOV lanes operate only during rush hours?
- Why are HOV lane restrictions typically enforced during construction projects, even when other lanes may be temporarily closed?
- Are HOV lanes effective?
- There are some areas with more than one HOV lane. Are these facilities coordinated with one another?
- How can I learn more about HOV facilities?
HOV is an acronym for High Occupancy Vehicle(s). HOV generally describes any vehicle carrying two or more persons on a single journey. Carpools, vanpools and buses are all considered to be HOV's.
Like HOV, SOV is an acronym for Single Occupancy Vehicle(s). SOV describes any vehicle carrying only the driver as the sole occupant.
HOV lanes are special lanes on a roadway reserved exclusively for the use of carpools, vanpools and/or buses. HOV lanes enable those who carpool or ride the bus to bypass traffic in the adjacent unrestricted general-purpose lanes. HOV lanes are sometimes called carpool lanes, diamond lanes, commuter lanes or busways. HOV lanes are provided on select sections of most of the freeways in the Los Angeles metropolitan area.
HOT is an acronym for High Occupancy/Toll. HOT lanes similar to HOV Lanes in that they allow vehicles that meet the minimum occupancy requirements to use the lanes. However, SOV users have to pay a monetary toll. HOT is most commonly used as a mechanism to increase utilization of HOV lanes in situations where HOV traffic volumes are well below the capacity of the lane(s). HOV users are typically not charged a toll when using HOT lanes. HOT lanes are provided on the I-15 Freeway in San Diego and on SR-91 in Orange County. Los Angeles County is planning a pilot project to convert the I-10 and I-110 HOV lanes to HOT lanes. Go to the ExpressLanes page for more information.
HOV lanes are intended to save time for carpool users and bus riders by enabling them to bypass areas of heavy traffic congestion. By giving carpool users and bus riders a quicker and more reliable ride, particularly during peak periods, HOV serves as a strong incentive for ridesharing, which in turn can help to manage congestion and contribute to improving air quality. HOV lanes provide commuters with an alternative to traffic congestion that is not always possible if all lanes on the roadway are open to general-purpose traffic.
HOV lanes are designed to be free of congestion and sometimes appear to be "empty," especially when compared with adjacent, congested, general-purpose lanes. However, when the number of people traveling in an HOV lane is compared to the adjacent general-purpose lanes, HOV lanes typically accommodate more people making them more efficient.
How many people an HOV lane accommodates will vary from corridor to corridor, depending on the level of bus service, the minimum occupancy requirement and the overall congestion level. An average HOV lane in Los Angeles County accommodates 1,300 vehicles and 3,300 people per hour during peak periods. This compares to 1,800 vehicles and 2,000 people per hour for general-purpose lanes during the same time periods.
According to Caltrans, the El Monte Busway HOV lanes on the I-10 Freeway east of Los Angeles accommodate as many passengers as three of the parallel general-purpose lanes during peak periods. To put it another way, it could take as much as three times as many vehicles to accommodate the same number of passengers in the general-purpose lanes as it does to accommodate that number of people in the HOV lanes. Therefore the HOV lanes may look "empty" compared to the parallel general-purpose lanes, even though they are actually accommodating more people.
HOV lanes benefit not only those who share the ride, but all roadway users and area residents and businesses. By encouraging carpools, vanpools and riding the bus, more passengers travel in fewer vehicles, which helps to manage congestion on heavily-traveled roadways. By reducing the number of vehicles on the road, HOV lanes can help reduce the amount of exhaust emissions and contribute to cleaner air.
HOV lanes are an essential tool for managing congestion along heavily-traveled corridors and benefit both the highway and transit systems by contributing to improving the overall quality of life. HOV lanes encourage travelers to carpool, vanpool or ride the bus which allows more people to be carried on the region's highway system and maximizes transportation resources.
These lanes enable regional transit services to fulfill their role of providing reliable service to transit users. If HOV lanes were eliminated entirely, or opened up to general-purpose traffic in areas where they exist, these benefits and a reliable, time-saving transportation option would be lost.
Most state Departments of Transportation and local transportation planning agencies sponsor programs to support ridesharing. In the Los Angeles area, the Southern California Association of Governments leads efforts to coordinate ridesharing opportunities through the "Southern California Rideshare" program. Southern California Rideshare is the nation's first and largest commuter assistance agency and for over 25 years has helped commuters find rideshare options.
Southern California Rideshare maintains a database of approximately 250,000 commuters and promotes alternatives to driving alone, including carpooling, vanpooling, taking transit, bicycling, walking and telecommuting, as well as "smart work" strategies such as flex-time or compressed work schedules. Southern California Rideshare can be contacted by calling 323.GO.METRO or by logging on to the Southern California Rideshare website .
While the most common type of HOV facility is a dedicated roadway lane, other types of HOV facilities include exclusive HOV ramps, bypass ramps at ramp meters, toll plazas and ferry docks, bus lanes, commuter parking lots with direct connections to HOV lanes and reserved parking spaces for carpools and vanpools.
HOV lanes look like any other roadway lane, except that they are typically delineated with signs and diamonds painted on the pavement. Although the lanes may look similar to any other roadway lanes, there is a great deal of variety in the design and operation of HOV lanes. Some types of HOV lanes, called concurrent flow lanes, are adjacent to, and operate in the same direction as, the general-purpose lanes.
Others types, called contraflow lanes, operate in the opposite direction of the adjacent general-purpose lanes effectively enabling HOV users to drive on the "wrong" side of the roadway with barriers separating them from oncoming traffic.
Reversible HOV lanes are usually placed in the highway median and run in one direction in the morning and then the opposite direction in the afternoon. Busways are usually physically separated from adjacent lanes and are reserved for bus use only. HOV lanes are delineated by a variety of methods, including barriers, buffer areas, and pavement markings.
Nearly all the HOV lanes in the Los Angeles metropolitan area are concurrent flow lanes located closest to the median and divided from the general-purpose lanes by a painted solid double yellow and single white line. HOV traffic is generally able to enter and exit the HOV lane from the adjacent general-purpose lanes at strategically located and clearly-marked intervals. Entering or exiting the HOV lanes from outside of the designated areas is a violation of the California State Vehicle Code and can result in a fine of up to $381 for the first offense.
Currently, there are some 126 HOV freeway projects in 27 metropolitan areas in the U.S. These HOV facilities include over 1,000 route miles. There are more HOV lanes on arterials, especially those related to bus-only applications .
The Clean Air Act Amendments of 1990 and the Transportation Equity Act of the 21st Century (TEA 21) specifically encourage states to consider and construct, where feasible, HOV lanes in areas experiencing air quality or traffic congestion problems. Most state Departments of Transportation have the legal authority to regulate the use as long as the rules are applied fairly and serve a public benefit.
In the State of California, §21655.5 of the Vehicle Code prescribes the ability of the State Department of Transportation to authorize or permit exclusive or preferential use of highway lanes for high occupancy vehicles. In addition, Proposition C which was passed in 1990 by the voters of Los Angeles County, specifically designates funds for highway improvements that benefit transit, i.e. HOV lanes.
The successful operation of all HOV facilities relies greatly on state and local police officers to monitor and enforce HOV lane requirements. In Washington State, a "HERO" program adds an element of self-enforcement, by encouraging commuters to report HOV lane violators to the State Police. In California, the California Highway Patrol has the primary responsibility for monitoring and enforcing HOV lane requirements.
Violators can be stopped and cited by the enforcement officer monitoring the HOV lane or simply re-directed back into the general-purpose lanes. Fines accompanying the citation vary from state to state, from about $50 in Florida and Massachusetts to over $381 in California depending on the number of citations offenders have received.
17. Why do some HOV lanes allow a minimum of two passengers per vehicle, while others require a minimum of three?
Occupancy requirements for HOV lanes are set according to local travel conditions, levels of existing congestion, and projected use of the lanes. If there are a high number of existing two-person carpools, then letting them all in to the HOV lane might cause congestion in the lane. If there are not enough three-person carpools and buses, then the lane might be perceived by the public to be underutilized.
In all cases, entry requirements are designed to allow for reliable and efficient travel in the HOV lanes, without allowing the lanes to become congested, or perceived by the public to be underutilized. The balancing of these objectives can be difficult.
Some states, in an effort to achieve this balance, have experimented with entry rules, changing them by time of day or raising or lowering the number of vehicles that can use the facility. This is the case on the I-10 Freeway HOV lanes (El Monte Busway) in Los Angeles.
California state legislative changes have reduced the minimum occupancy requirement for carpools on the El Monte Busway from three persons to two persons, in response to public perceptions that the facility was underutilized.
The result has been increased congestion in the HOV lanes during peak periods, prompting the California State Legislature to change the minimum requirement to three-person carpools during the peak periods. With the exception of the El Monte Busway, the minimum carpool occupancy requirement for all HOV lanes in the Los Angeles metropolitan area is two persons per vehicle.
All states with HOV lanes count children and infants as passengers.
Motorcycles are permitted by federal law to use HOV lanes, even though they typically carry only one passenger. The explanation for the federal law is that allowing motorcycles to use HOV lanes keeps them moving, and it is considered safer to keep two-wheel vehicles moving than it is to have them traveling in start-and-stop traffic conditions.
The individual states can choose to override this provision of federal law, if they determine that there is an inherent safety risk by allowing motorcycles to use HOV lanes. In the State of California, motorcycles are permitted to use HOV facilities unless a traffic control device specifically prohibits them.
Not usually, although in isolated cases two-seater vehicles are permitted. Most states try to maintain a consistent approach to enforcing entry requirements and do not allow exceptions to entry rules for two-seater vehicles. The entry rule is based not on how full the car or truck is, but on how many passengers are in it. In California, two-seater vehicles are not permitted to use HOV facilities with a three-person occupancy requirement.
21. Are there any vehicles that are prohibited from using HOV lanes, even with the appropriate number of passengers?
Many states prohibit oversized vehicles, such as tractor-trailer trucks, from using HOV facilities for safety reasons. For the same reasons, parades, processions and certain types of heavy trucks and large recreational vehicles are sometimes precluded from using HOV lanes. Oversized vehicles are prohibited from using HOV lanes in the State of California.
In some states, certain types of Single Occupant Vehicles are permitted to use HOV lanes, but this situation typically only applies in limited circumstances for vehicles serving a specific function (for example, roadside assistance and emergency service vehicles, and commercial passenger vehicles traveling between destinations with no passengers) or for special types of vehicles that feature certain characteristics (for example, low-emission vehicles).
In California, for example, ultra-low-emission Vehicles (ULEV's) are permitted to use HOV facilities regardless of the number of passengers, provided the vehicle has been registered with the State Department of Motor Vehicles and displays the appropriate state-issued decal certifying that it is permitted to use HOV facilities with less than the designated minimum occupancy requirement.
Studies have shown that HOV lanes are frequently as safe as, and in many cases, safer than, unrestricted lanes. The safest HOV lanes are those physically separated from the adjacent lanes with a concrete barrier.
Operating hours vary from state to state and within states. Some states operate their HOV lanes only during rush hours, when traffic is heaviest and HOV lanes are most likely to save time for carpool users. During off-peak hours, these states either open the lanes to all traffic or simply close them until the next scheduled opening.
Other states operate their HOV facilities twenty-four hours a day. This approach helps to provide ridesharing incentives at all times and provides travel-time savings during periods of unexpected congestion (for example, during special events or when there is an incident or accident).
25. Why are HOV lane restrictions typically enforced during construction projects, even when other lanes may be temporarily closed?
Most states will continue to enforce HOV lane restrictions during construction projects as part of their efforts to reduce traffic in construction areas by encouraging people to use carpools, vanpools and buses. In addition, the maintenance of HOV facilities during construction projects may be critical to helping buses maintain reliable schedules so people can make connections and appointments on time.
In some instances, HOV facilities have been specifically created for the duration of the construction project to promote carpool, vanpool and bus usage as a means of managing traffic during construction.
Though results vary from state to state, nearly every state with HOV lanes reports that ridesharing and overall corridor person moving efficiency has increased since HOV lanes have been opened. The Los Angeles County HOV system accommodates more people than any other HOV system in the United States and is one of the few HOV systems that has been able to sustain a growth in carpool users.
The 2009 Caltrans HOV Annual report stated that Los Angeles County’s
HOVSystem carried approximately 331,000 vehicles or 780,000 people per day. On average, our system carried approximately 1,300 vehicles per hour or 3,300 people per hour during peak hours. These volumes well exceeded the minimum expected value of 800 vehicles per hour or 1,800 people per hour as specified in Caltrans’ HOV Guidelines for Planning, Design and Operation and have led us to continue the HOV Program development throughout Los Angeles County.
27. There are some areas with more than one HOV lane. Are these facilities coordinated with one another?
Many states and regions develop HOV "system plans" to ensure that they are prepared to meet future HOV needs while coordinating the development of existing facilities. The states of Washington, California and Texas, and the City of Nashville, Tennessee, all have conducted system planning to coordinate area-wide HOV facilities. As is the case in the Los Angeles metropolitan area, the development of the HOV system is only partially completed.
The Links page at this website provides a list of links to other sites on the World Wide Web that detail information regarding HOV, and Los Angeles-area regional transportation planning and service activities. This site also provides the ability to contact staff at Metro where you can request information about HOV and other transportation services or specifically about the Los Angeles County HOV Performance Program