HOV lanes may be a single traffic lane within the main roadway with distinctive markings or a separated roadway with one or more traffic lanes parallel to the general lanes or with an overpass, above or below the general lanes. For example, Interstate 110 in California has four HOV lanes on an upper deck.

HOV detour lanes are intended to allow carpool, bus and police traffic to avoid common congestion areas in many locations. An HOV lane can function as a reversible lane, working in the direction of the dominant traffic flow in both the morning and afternoon. All lanes of a 10-mile (16.1 km) stretch of Interstate 66 in the suburbs of Washington, D.C., are treated as HOV during rush hour in the main direction of flow.[11]​.

The speed difference between the HOV and general purpose lanes creates a potentially dangerous situation if the HOV lanes are not separated by a barrier. A study by the Texas Transportation Institute found that HOV lanes without barriers caused a 50% increase in the number of injury accidents.[36]

Commercial access and transit lane

A business access and transit lane (BAT) is a type of HOV lane that allows all traffic to enter the lane for a short distance to access other streets and business entrances.[37]​.

High Occupancy Toll Lane

Because some HOV lanes are not used at full capacity, users of low or single occupancy vehicles can use an HOV lane if they pay a toll. This scheme is known as high-occupancy toll lane (or HOT lanes), and has been mainly introduced in the United States. The first practical implementation was California's 91 Express Lanes, previously privately tolled, in Orange County, California ("Orange County, California") in 1995, followed in 1996 by Interstate 15 north of San Diego ("San Diego, California").[38][39] According to the Texas A&M Transportation Institute, in 2012 there were 294 miles of HOT/Express lane corridors and 163 miles of HOT/Express lane corridors under construction in the United States.[40]​.

Solo drivers can use the HOV lanes upon payment of a "Tax (tax)" fee that varies depending on demand. Tolls change throughout the day based on real-time traffic conditions, which is intended to manage the number of cars in the lanes to maintain good travel times.[41]​[42]​.

Proponents claim that all motorists benefit from HOT lanes, even those who choose not to use them. This argument only applies to projects that increase the total number of lanes.[43] Proponents also claim that HOT lanes incentivize the use of public transportation and ride-sharing. There has been controversy over this concept, and HOT systems have been called "Lexus" lanes, as critics see this new pricing scheme as a benefit for the rich.[44]​.

HOT tolls are collected through toll houses, automatic license plate recognition, or electronic toll collection. Some systems use RFID transmitters to monitor lane entry and exit and charge drivers based on demand. Typically, tolls increase as traffic density and congestion in toll lanes increases, a policy known as congestion pricing. The objective of this pricing system is to minimize traffic congestion in the lanes.[45]​[46]​.

Qualification for HOV status varies depending on the scheme, but the following vehicles may be included:.

New York City's HOV lane codes prior to 2008 did not allow the use of motorcycles, resulting in fines for motorcycle drivers and complaints from the American Motorcyclist Association, but have since been revised to comply with the federal regulations mentioned above.[51][54][55]​.

In some jurisdictions, such as Ontario, Canada, taxis and airport limousines are allowed to use HOV lanes even if there are no passengers, because that vehicle "will be able to return to service more quickly after dropping off a passenger or arriving earlier to pick them up, thus moving more people to their destinations in fewer vehicles."[56]​.

In Virginia, the San Francisco Bay Area, Houston, and other places with HOV lanes, travelers form sluglines&action=edit&redlink=1 "Slugging (vehicle) (not yet written)") in which drivers pick up one or more passengers from a designated "casual carpool" or slug lines to travel in HOV lanes; The driver stops near the sluglines and calls out his destination, and the people in line going to that destination get into the car in order of arrival.[57]​.

Fines are typically imposed on drivers of unauthorized vehicles using the lanes.[58]​.

After the introduction of HOVs, some drivers placed inflatable dolls in the passenger seat, a practice that persists today, although it is now illegal.[58]​ In 2005, cameras capable of distinguishing between human beings and mannequins or dolls were tested in the United Kingdom.[59]​.

In the United States, law enforcement agencies have documented various methods used by drivers to circumvent HOV occupancy regulations:

In early 2006, an Arizona woman alleged that she had been improperly ticketed for using the HOV lane because the fetus she was carrying justified her use of the lane, while pointing out that Arizona traffic laws do not define what constitutes a person. However, a judge later ruled that to be considered a "person" under Arizona traffic laws, a person must occupy a "separate and distinct" space in a vehicle.[60]​ Likewise, in California, in order to use HOV lanes, there must be two (or, if indicated, three) separate people occupying seats in a vehicle, and a fetus does not count toward this requirement.[61]​.

In 2009 and 2010, non-compliance rates in HOV lanes in Brisbane, Australia were found to be approaching 90%. Strengthened law enforcement led to greater compliance, the average duration of bus trips was reduced by approximately 19%, and the total number of people transported increased by 12%.[62]​.

In February 2010, a 61-year-old woman attempted to pass off a life-sized mannequin as a passenger to use the HOV lane in New York state. A police officer on routine HOV patrol became suspicious when he observed the alleged passenger wearing sunglasses and using the visor on a cloudy morning. When the officer approached the vehicle, he discovered that the “passenger” was actually a mannequin wearing lipstick, designer glasses, a long wig, and a blue sweater. The driver received a traffic ticket for using the HOV lane without a human passenger, which carries a fine of $135 in 2010 and two points on the driver's license.[63][64]​.

In January 2013, a motorist tried to claim that his company's bylaws, which had been placed unfastened in the passenger seat, constituted a person, citing the principle of corporate personhood, and the California State Vehicle Code, which defines a person as "individuals and corporations." This argument was rejected in traffic court, where the presiding judge commented: "Common sense says that carrying a sheaf of papers in the front seat does not alleviate traffic congestion."[65]

In March 2015, a motorist attempted to use a cardboard cutout of actor Jonathan Goldsmith to access an HOV lane in Fife, Washington. The officer noted that other drivers had used sleeping bags in previous attempts to enter the HOV lane.[66]

In July 2022, a pregnant woman in Texas alleged that her fetus counted as a passenger for purposes of HOV lane use following the ruling in Dobbs v. Jackson Women's Health Organization and the subsequent consideration of fetuses as persons under Texas law.[67]​

According to 2009 US Census data, 76% drive alone to work and only 10% carpool. For suburban workers working in a city, the solo driving rate is 82%.[68]​.

Some underutilized HOV lanes in several states have been converted to high-occupancy toll (HOT) lanes, which offer lone drivers access to HOV lanes for a toll.[68]​.

HOV lanes are also an effective way to manage traffic after natural disasters, as seen in New York after Hurricane Sandy in October 2012. At the time, Mayor Bloomberg banned passenger cars with fewer than three occupants from entering Manhattan. The restriction affected all bridges and tunnels entering the city, except the George Washington Bridge.[69]​.

Critics have argued that HOV lanes are underused. It is unclear whether the HOV lanes are used enough to offset delays in the other mixed-use lanes.[70]​[71]​.

The situation has caused social problems in Indonesia, where some people become "car jockeys" - people who make a living by offering drivers to fill their car to meet the occupancy limit. The situation reportedly caused people to become unemployed for doing so, increased congestion and allowed parents to profit from their babies.[72][73][74][75][35][76][77][78]​.

HOV lanes may be a single traffic lane within the main roadway with distinctive markings or a separated roadway with one or more traffic lanes parallel to the general lanes or with an overpass, above or below the general lanes. For example, Interstate 110 in California has four HOV lanes on an upper deck.

HOV detour lanes are intended to allow carpool, bus and police traffic to avoid common congestion areas in many locations. An HOV lane can function as a reversible lane, working in the direction of the dominant traffic flow in both the morning and afternoon. All lanes of a 10-mile (16.1 km) stretch of Interstate 66 in the suburbs of Washington, D.C., are treated as HOV during rush hour in the main direction of flow.[11]​.

The speed difference between the HOV and general purpose lanes creates a potentially dangerous situation if the HOV lanes are not separated by a barrier. A study by the Texas Transportation Institute found that HOV lanes without barriers caused a 50% increase in the number of injury accidents.[36]

Commercial access and transit lane

A business access and transit lane (BAT) is a type of HOV lane that allows all traffic to enter the lane for a short distance to access other streets and business entrances.[37]​.

High Occupancy Toll Lane

Because some HOV lanes are not used at full capacity, users of low or single occupancy vehicles can use an HOV lane if they pay a toll. This scheme is known as high-occupancy toll lane (or HOT lanes), and has been mainly introduced in the United States. The first practical implementation was California's 91 Express Lanes, previously privately tolled, in Orange County, California ("Orange County, California") in 1995, followed in 1996 by Interstate 15 north of San Diego ("San Diego, California").[38][39] According to the Texas A&M Transportation Institute, in 2012 there were 294 miles of HOT/Express lane corridors and 163 miles of HOT/Express lane corridors under construction in the United States.[40]​.

Solo drivers can use the HOV lanes upon payment of a "Tax (tax)" fee that varies depending on demand. Tolls change throughout the day based on real-time traffic conditions, which is intended to manage the number of cars in the lanes to maintain good travel times.[41]​[42]​.

Proponents claim that all motorists benefit from HOT lanes, even those who choose not to use them. This argument only applies to projects that increase the total number of lanes.[43] Proponents also claim that HOT lanes incentivize the use of public transportation and ride-sharing. There has been controversy over this concept, and HOT systems have been called "Lexus" lanes, as critics see this new pricing scheme as a benefit for the rich.[44]​.

HOT tolls are collected through toll houses, automatic license plate recognition, or electronic toll collection. Some systems use RFID transmitters to monitor lane entry and exit and charge drivers based on demand. Typically, tolls increase as traffic density and congestion in toll lanes increases, a policy known as congestion pricing. The objective of this pricing system is to minimize traffic congestion in the lanes.[45]​[46]​.

Qualification for HOV status varies depending on the scheme, but the following vehicles may be included:.

New York City's HOV lane codes prior to 2008 did not allow the use of motorcycles, resulting in fines for motorcycle drivers and complaints from the American Motorcyclist Association, but have since been revised to comply with the federal regulations mentioned above.[51][54][55]​.

In some jurisdictions, such as Ontario, Canada, taxis and airport limousines are allowed to use HOV lanes even if there are no passengers, because that vehicle "will be able to return to service more quickly after dropping off a passenger or arriving earlier to pick them up, thus moving more people to their destinations in fewer vehicles."[56]​.

In Virginia, the San Francisco Bay Area, Houston, and other places with HOV lanes, travelers form sluglines&action=edit&redlink=1 "Slugging (vehicle) (not yet written)") in which drivers pick up one or more passengers from a designated "casual carpool" or slug lines to travel in HOV lanes; The driver stops near the sluglines and calls out his destination, and the people in line going to that destination get into the car in order of arrival.[57]​.

Fines are typically imposed on drivers of unauthorized vehicles using the lanes.[58]​.

After the introduction of HOVs, some drivers placed inflatable dolls in the passenger seat, a practice that persists today, although it is now illegal.[58]​ In 2005, cameras capable of distinguishing between human beings and mannequins or dolls were tested in the United Kingdom.[59]​.

In the United States, law enforcement agencies have documented various methods used by drivers to circumvent HOV occupancy regulations:

In early 2006, an Arizona woman alleged that she had been improperly ticketed for using the HOV lane because the fetus she was carrying justified her use of the lane, while pointing out that Arizona traffic laws do not define what constitutes a person. However, a judge later ruled that to be considered a "person" under Arizona traffic laws, a person must occupy a "separate and distinct" space in a vehicle.[60]​ Likewise, in California, in order to use HOV lanes, there must be two (or, if indicated, three) separate people occupying seats in a vehicle, and a fetus does not count toward this requirement.[61]​.

In 2009 and 2010, non-compliance rates in HOV lanes in Brisbane, Australia were found to be approaching 90%. Strengthened law enforcement led to greater compliance, the average duration of bus trips was reduced by approximately 19%, and the total number of people transported increased by 12%.[62]​.

In February 2010, a 61-year-old woman attempted to pass off a life-sized mannequin as a passenger to use the HOV lane in New York state. A police officer on routine HOV patrol became suspicious when he observed the alleged passenger wearing sunglasses and using the visor on a cloudy morning. When the officer approached the vehicle, he discovered that the “passenger” was actually a mannequin wearing lipstick, designer glasses, a long wig, and a blue sweater. The driver received a traffic ticket for using the HOV lane without a human passenger, which carries a fine of $135 in 2010 and two points on the driver's license.[63][64]​.

In January 2013, a motorist tried to claim that his company's bylaws, which had been placed unfastened in the passenger seat, constituted a person, citing the principle of corporate personhood, and the California State Vehicle Code, which defines a person as "individuals and corporations." This argument was rejected in traffic court, where the presiding judge commented: "Common sense says that carrying a sheaf of papers in the front seat does not alleviate traffic congestion."[65]

In March 2015, a motorist attempted to use a cardboard cutout of actor Jonathan Goldsmith to access an HOV lane in Fife, Washington. The officer noted that other drivers had used sleeping bags in previous attempts to enter the HOV lane.[66]

In July 2022, a pregnant woman in Texas alleged that her fetus counted as a passenger for purposes of HOV lane use following the ruling in Dobbs v. Jackson Women's Health Organization and the subsequent consideration of fetuses as persons under Texas law.[67]​

According to 2009 US Census data, 76% drive alone to work and only 10% carpool. For suburban workers working in a city, the solo driving rate is 82%.[68]​.

Some underutilized HOV lanes in several states have been converted to high-occupancy toll (HOT) lanes, which offer lone drivers access to HOV lanes for a toll.[68]​.

HOV lanes are also an effective way to manage traffic after natural disasters, as seen in New York after Hurricane Sandy in October 2012. At the time, Mayor Bloomberg banned passenger cars with fewer than three occupants from entering Manhattan. The restriction affected all bridges and tunnels entering the city, except the George Washington Bridge.[69]​.

Critics have argued that HOV lanes are underused. It is unclear whether the HOV lanes are used enough to offset delays in the other mixed-use lanes.[70]​[71]​.

The situation has caused social problems in Indonesia, where some people become "car jockeys" - people who make a living by offering drivers to fill their car to meet the occupancy limit. The situation reportedly caused people to become unemployed for doing so, increased congestion and allowed parents to profit from their babies.[72][73][74][75][35][76][77][78]​.