Structures Design Guidelines | Jan 2009
7 - Widening and Rehabilitation |

## 7.2 Classifications and Definitions

### 7.2.1 Major Widening

A “Major Widening” is new construction work to an existing bridge facility which doubles the total number of traffic lanes or bridge deck area of the existing bridge facility. The area to be calculated is the transverse coping-to-coping dimension.

### 7.2.2 Minor Widening

A “Minor Widening” is new construction work to an existing bridge facility that does not meet the criteria of a major widening.

Commentary: The term “facility” describes the total number of structures required to carry a transportation route over an obstruction. In this context, adding two lanes of traffic to one bridge of twin, two-lane bridges would be a minor widening because the total number of lanes of resulting traffic, (six) in the finished “facility” is not twice the sum number of lanes of traffic, (four), of the unwidened, existing twin bridges.