California Department of Transportation
Postmile Entries in BOLD type show DISTRICT-COUNTY-ROUTE. Other entries show postmile prefix followed by postmile to the nearest hundredth of a mile. Prefixes of R, M, and N refer to re-aligned routes. Prefix L refers to a section or route paralleling another route. When the route is on the deck of the bridge, the postmile is recorded at the beginning of the structure (i.e. the lowest postmile on the bridge). When the route goes under the structure, the postmile is recorded on the underpassing route where the structure is first encountered. All other measuerments in this publication are given in meters.
OU "O" Indicates that the route is carried on the deck of the structure.
"U" Indicates a route crossing under the structure.
The official structure number assigned by CalTrans. The Bridge Number Suffix carries information about the function of the structure.
Structure Name or Route Information The structure name assigned by Structure Maintenance and Investigations or miscellaneous route information.
Structure Types
First character (Material):

  • 1 = Concrete
  • 2 = Concrete continuous
  • 3 = Steel
  • 4 = Steel continuous
  • 5 = Prestressed concrete
  • 6 = Prestressed concrete continuous
  • 7 = Wood or timber
  • 8 = Masonry
  • 9 = Aluminum, wrought iron, or cast iron
  • 0 = Other

  • Second & Third characters (Design):

  • 01 = Slab
  • 02 = Stringer/Multi-beam or Girder
  • 03 = Girder and Floorbeam System
  • 04 = Tee Beam
  • 05 = Box Beam or Girders - Multiple
  • 06 = Box Beam or Girders - Single or Spread
  • 07 = Frame (except frame culverts)
  • 08 = Orthotropic
  • 09 = Truss - Deck
  • 10 = Truss - Thru
  • 11 = Arch - Deck
  • 12 = Arch - Thru
  • 13 = Suspension
  • 14 = Stayed Girder
  • 15 = Movable - Lift
  • 16 = Movable - Bascule
  • 17 = Movable - Swing
  • 18 = Tunnel
  • 19 = Culvert
  • 21 = Segmental Box Girder
  • 22 = Channel Beam
  • 00 = Other
    City CalTrans alphabetic code for the city or government land within whose limits the bridge exists.
    The length of the structure (meters)
    Width The out-to-out width of the structure to the nearest tenth of a meter. For through structures, the lateral clearance between superstructure members. For flared structures, the minimum deck width. No width is shown for non-grade-top culverts or structures not carrying vehicular traffic, such as underpasses or pedestrian overcrossings.
    The number of span in the structure. Upper-level spans of double deck structures are not included in this count.
    VC Over
    The minimum vertical clearance over the traveled way (meters).
    The minimum width of left and right sidewalks or curbs, to the nearest tenth of a meter. Where this value is 1 meter or greater, the structure is considered to carry pedestrian traffic.
    The year of original construction. For some older bridges, this may be an estimate.
    Permit ratings are shown for information only. They should not be used for permit issuance. .
    The permit rating is usually a string of five characters showing permit capacity for 5,7,9,11, and 13 axle vehicles. Where a single character is shown, it represents an "administrative" rating.
    P Posting - See the Posting Table.