Carpool Lanes

Carpool lanes on Rt. 60Carpool lanes, also known as high occupancy vehicle (HOV) lanes or diamond lanes, maximize the capacity of freeways by providing incentives to use buses, vanpools, and carpools. They are designed to move more people per vehicle and to save travel time.

Through carpool programs, SANBAG strives to make the best use of existing facilities and maintain current and future highway mobility. Carpool lanes also reduce pollution and dependency on fossil fuels.

  • Carpool Lane Background
  • San Bernardino Carpool Lanes
  • Carpool Lane FAQs

Background on Carpool Lanes

Diamond lanes on an onrampA carpool lane is a dedicated freeway lane that is restricted to vehicles occupied by a required number of passengers -- usually two, but in some cases three. Recent changes in California legislation allow certain alternative fuel vehicles certified as ultra low emission to use carpool lanes, regardless of the number of occupants. These lanes are open only to carpool traffic, 24 hours per day, seven days per week.

Carpool lanes provide a reliable way to travel for commuters who share rides, ride the bus, or drive ultra-low emission vehicles. These lanes provide a strong incentive for people to rideshare and leave their cars at home. Today, the Southern California carpool system carries more people than any other carpool system in the United States and is one of the few systems in the country that has been able to sustain growth.

SANBAG, in cooperation with Caltrans, has funded and constructed 49miles of carpool lanes in San Bernardino County and is in various stages of planning, design, and construction for an additional 18 miles of carpool lane

The overall goals of carpool lanes are:

  • To maximize the people-carrying capacity of freeways by providing incentives to use buses, vanpools, and carpools
  • To boost future freeway capacity.

SANBAG strives to make the best use of existing facilities and to promote future freeway mobility by promoting programs that move more people in fewer vehicles. These programs also reduce pollution and dependency on fossil fuels.

Carpool lanes are designed to:

  • Improve the capacity of congested freeways by moving more people per vehicle;
  • Save travel time and increase trip reliability for lane users; and
  • Provide safe travel options for high occupancy vehicles without compromising the safety of regular freeway lanes.

In developing the carpool lane network, it is recognized that no single strategy will enhance mobility and resolve traffic congestion. Implementing a variety of carpool elements improves the overall efficiency of transportation systems. Examples of support facilities critical to the success of carpool lanes are:

  • Park and Ride lots,
  • Carpool direct-access ramps,
  • Intelligent Transportation Systems (ITS) applications, such as surveillance and carpool ramp bypasses, and
  • Support services, such as express buses, ride-matching, parking strategies, incident management and demand management programs.

San Bernardino County Carpool Lanes

Carpool lane construction on State Route 60San Bernardino County has 49 miles of carpool lanes, with plans for the construction of an additional 36miles in the near future. These lanes are part of the larger Southern California carpool lane network, which accounts for more than 437 lane miles in the metropolitan area. Most of the county's carpool lanes have been designed and constructed with funding from San Bernardino County's half-cent sales tax, Measure I, as well as other federal and state funding sources.

In San Bernardino County, 49 miles of carpool lanes are in operation along three separate freeways:

  • Interstate 10, from Los Angeles County Line to I 215;
  • State Route 71, the Chino Valley Freeway;
  • State Route 60;
  • State Route 210 from Los Angeles County line to I 215;

SANBAG is currently working with Caltrans to fund and construct an additional 36 miles of carpool lanes along the following corridors:

Frequently Asked Questions About Carpool Lanes

There are many questions often asked regarding carpool lane systems. Answers to some of these frequently asked questions are provided below.

  • What are carpool lanes?
    Carpool lanes are special lanes on a roadway reserved exclusively for the use of carpools, vanpools, buses and certain ultra-low emission vehicles. These lanes enable those who carpool, ride the bus or drive certified vehicles to bypass traffic in regular freeway lanes. Carpool lanes are provided on selected sections of most of the freeways in Southern California.
  • What are other names for carpool lanes?
    Carpool lanes are sometimes called HOV (high occupancy vehicle) lanes, diamond lanes, commuter lanes, or busways.
  • What is a HOT lane?
    HOT is an acronym for High Occupancy/Toll. HOT lanes are carpool lanes that allow use by single occupant vehicle drivers who have paid a toll. HOT lanes are designed to increase the use of carpool lanes when these lanes are not being used to their full capacity. At times carpoolers are not charged a toll when using HOT lanes. HOT lanes are currently in operation on Interstate 15 in San Diego and on State Route 91 in Orange County.
  • What is the main objective of a carpool lane?
    The main objective of a carpool lane is to improve the efficiency of freeway systems by increasing the number of people per vehicle.
  • How do carpool lanes work?
    Carpool lanes are intended to save time for carpool users, bus riders, and drivers of certain ultra-low emission vehicles by enabling them to bypass areas of heavy traffic congestion. By giving these drivers and riders a quicker and more reliable ride, carpool lanes offer a strong incentive for ridesharing, which in turn can help to manage congestion and contribute to improving air quality. Carpool 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.
  • Sometimes it seems the carpool lanes are empty, so does that mean they're not working?
    Carpool 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 a carpool lane is compared to general-purpose lanes, carpool lanes typically accommodate more people, making them more efficient. An average carpool lane in Southern California moves 1,200 vehicles and 3,100 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.
  • If I drive alone, why should I support carpool lanes when I can't use them?
    Carpool lanes benefit not only those who share the ride, but all roadway users and area residents and businesses. By encouraging ridesharing, more passengers travel in fewer vehicles. By reducing the number of vehicles on the road, carpool lanes can cut the amount of exhaust emissions and contribute to cleaner air.
  • What would happen if carpool lanes were eliminated?
    Carpool lanes are essential for managing congestion along heavily traveled freeways. These lanes encourage travelers to carpool, vanpool, or ride the bus, which maximizes transportation resources. Carpool lanes also enable transit services to provide reliable service to users. If carpool lanes were eliminated entirely or opened to general-purpose traffic, these benefits and a reliable, time saving transportation option would be lost.
  • Where can I find out about ridesharing opportunities?
    In San Bernardino County, SANBAG funds a variety of programs to help commuters with ridesharing arrangements, as well as to help employers with their ridesharing program. Other transportation planning agencies fund and implement programs to support ridesharing and are the lead agencies in each of their counties. For more information, please contact the Riverside County Transportation Commission, the Los Angeles County Metropolitan Transportation Authority, the Orange County Transportation Authority and the Ventura County Transportation Commission.