The Design Lane Load has a uniformly distributed load of how many kip/ft in the longitudinal direction?

• A. 1.28 kip/ft
• B. 0.64 kip/ft
• C. 0.32 kip/ft
• D. 0.80 kip/ft

Answer: (B)

Design Lane Load is the uniform line load used to represent traffic in a single lane along the bridge deck, spread out as a constant w in the longitudinal direction. In standard design practice, the per-lane value is taken as 0.64 kips per foot. This means that, for analysis, one lane carrying traffic contributes an equivalent 0.64 kip of load for every foot of span length. If you had two lanes carrying traffic simultaneously, you’d sum the lane loads (about 1.28 kip/ft), which is why other numbers like 1.28 or 0.32 aren’t the per-lane standard values. The 0.64 kip/ft value is the conventional design lane load used to size girders and deck components.