Determining if a structure is a BRI

Methods used to measure a bridge and determine if it qualifies as "BRI."

Definition of "BRI"

  • A "BRI" is a highway bridge structure that meets the Massachusetts General Laws (MGL) but not the federal definition of a bridge.
  • MGL recognize structures having a span greater than 10 feet as bridges.
  • Federal regulations define a bridge as a structure having a span greater than 20 feet.
  • Thus, a "BRI" has a span greater than 10’ but not greater than 20'.
  • The "span" is the distance between adjacent centerlines of bearings.
  • The bridge must be on and carry a public way.

How to measure the span distance

  • MassDOT takes all span measurements along the centerline of the roadway.
  • For bridges that have defined centerlines of bearings:
    • Measure the total distance from the centerline of bearings on one abutment to the centerline of bearings on the other abutment. (See Figure 1)
  • For bridges that do not have defined centerlines of bearings, such as arches, culverts and those bridges where the ends of the beams are encased so that there is no centerline of bearings:
    • Measure the clear opening between the breastwalls of abutments, the spring lines of arches, or extreme ends of openings for multiple boxes. (See Figures 2a, 2b, 2c)
  • For bridges that consist of large size pipes:
    • Measure the maximum diameter of the pipe, or, in the case of multiple pipes, the maximum total distance across all pipes provided that the clear distance between pipes is less than half the diameter of the smaller contiguous pipe. (See Figure 3)

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