California Department of Transportation

45' Buses (Greater than 40' up to 45')


45' Bus: On this web page, a 45' bus refers to a bus that is longer than 40 feet but not more than 45 feet. (Note: A vehicle combination, e.g. a bus towing a vehicle or trailer, may be up to 65 feet length. If the single-unit bus is 40 feet or less in length, the combination is not subject to the 45' motorhome restrictions.)

Bus: California Vehicle Code (CVC) Section 233 defines "bus" as: "(a) …any vehicle… …designed, used, or maintained for carrying more than 15 persons including the driver." Or, "(b) A vehicle designed, used, or maintained for carrying more than 10 persons, including the driver, which is used to transport persons for compensation or profit, or is used by any nonprofit organization or group..." Tour buses are also commonly referred to as "coaches," "motorcoaches" and "motor carriers of passengers." This web page deals with buses operating as "passenger transportation vehicles" as defined by CVC 464.

Tour bus: CVC 612 states: "Tour bus" means a bus designed for carrying more than 16 passengers and the driver, which is operated by or for a charter-party carrier of passengers, as defined in Section 5360 of the Public Utilities Code (PUC). This definition includes operation of a "passenger stage corporation" as defined in PUC 226, or any carrier of passengers required to register with the California Public Utilities Commission pursuant to PUC 3902.

KPRA: Kingpin-to-rearmost-axle distance on a truck tractor-semitrailer.

CVC: California Vehicle Code.


The basic California length law for vehicles is 40 feet unless specifically exempted. The law exempts buses up to 45 feet, but only on certain routes. In recent years, the tour bus manufacturing industry increased its standard bus length from 40 feet to 45 feet to increase capacity, and to accommodate requirements of the Americans with Disabilities Act. The California Bus Association estimates that 78% of new bus sales are 45-foot models. These longer buses can operate safely on many highways, but may encounter problems on narrow two-lane roads with tight curves or without shoulders. Therefore, Caltrans restricts certain route segments to buses over 40 feet long.


Vehicle Length: The basic vehicle length limit in California is stated in the California Vehicle Code (CVC) Section 35400(a): "A vehicle may not exceed a length of 40 feet."

Federal Law: In 1991, the federal Intermodal Surface Transportation Efficiency Act (ISTEA) required states to allow buses up to 45 feet long on National Network (NN) highways, which are comprised of primarily interstates. ISTEA allowed states to determine which routes off the NN that 45' buses may use to pick up or deliver passengers.

State Law: The federal ISTEA allows 45' buses in California on the National Network (NN) and mandates that the buses be allowed reasonable access to points of loading and unloading. In 1995, at the request of bus companies and bus associations, Caltrans reviewed the viability of allowing 45' buses on routes beyond the NN using an engineering analysis. The California law that allows buses up to 45 feet is CVC Section 35400(b)(10)(A).


The following sources illustrate the routes that allow 45' buses:

On-Line Map: See the on-line map at: Click on the red numbers to open each regional map. The green routes allow 45' buses and the red routes prohibit them.

Restricted Route List: An on-line list of route segments that restrict 45' buses is at: The list includes beginning and ending post miles and intersecting streets or highways of each segment.

Stopping for Services: 45' buses may exit the designated route for fuel, food, and lodging provided the access is signed and the service is within one road mile of the "identified" exit. The exit must be signed to show that the service route has been evaluated and approved by State and local engineers. This "Service Access" sign shows an "S" on the back of a truck, as illustrated below. These signs were intended for large trucks, and are located primarily on the interstates.

Sign #

For more information on service access, see the web page Service Access Routes.

City and County Access Roads: Caltrans has jurisdiction over State routes only. 45' buses are allowed on certain State routes, but not necessarily on local roads. Cities and counties have jurisdiction over local roads. To inquire about bus access on local roads, contact the appropriate city or county public works department.


Access Routes: 45' buses may travel on virtually every State route EXCEPT those signed with a 30-foot kingpin-to-rear-axle (KPRA) advisory sign. This sign advises trucks with a KPRA of more than 30 feet not to use the route. There are also KPRA advisory signs with 32, 34, 36, and 38 feet. These advisories that are 32 feet and higher ALLOW 45' buses to use the routes. See the advisory sign below.

Advisory Route
Indicates KPRA length advised

45-Foot Bus Design Vehicle: The turning characteristics of the 45-foot bus can now be evaluated with more precision using modern computer methods rather than comparing them with the truck KPRA routes. The Caltrans Highway Design Manual (HDM) has a new design vehicle for the 45-foot bus called the " 45' Bus and Motorhome Design Vehicle." This vehicle is in the HDM on Page 400-20, Figure 404.5F, at:


To request that a road be opened up to 45' buses, follow these instructions:

State routes: Caltrans has already analyzed State routes for their ability to accommodate 45-foot buses, which is the worst case bus over 40 feet in length. However, highway improvement projects that change the geometrics, as well as the new computer methods, may justify a new evaluation. To inquire about a possible new access route, contact Caltrans Headquarters at (916) 654-5741 for referral to the appropriate Caltrans district staff.

City and County Roads: To request a city or county road evaluation for 45' bus access, contact the appropriate city or county public works department. If the city or county road intersects a State highway, Caltrans will also need to evaluate the exit and entrance ramps.


A bus driver needs a passenger vehicle endorsement on a Class B Commercial Driver's License issued by the California Department of Motor Vehicles (DMV). More information is found in the latest version of the California Commercial Driver Handbook published by DMV.


The following trade organizations may be good sources of information and networking.

California Bus Association
11020 Commercial Parkway
Castroville, CA 95012
(831) 633-1755 or
(800) 664-2877
Fax (831) 633-1934
American Bus Association
1100 New York Ave., N.W., Suite 1050
Washington, DC 20005-3934
(202) 842-1645,
Fax: (202) 842-0850
United Motorcoach Association
113 South West Street, 4th Floor
Alexandria, VA 22314-2824
(703) 838-2929 or
(800) 424-8262
Fax: (703) 838-2950


Caltrans Legal Truck Size & Weight Work Group
Casey Robb
Manuel Fonseca
General number (916) 654-5741

E-mail: Legal Truck Access Branch.

Return to the Caltrans "45' Bus & Motorhome" page.

Revised 2/25/15.