Dynamic Load Allowance (IM) | AASHTO | Minimum Vehicle Design Speed

[engjg]

Is there a minimum vehicle design speed where AASHTO requires the dynamic load allowance be considered, or are they silent to it and so conservatively it would need to apply at all design speeds? Application is design of access hatch for underground vault in sidewalk that can be driven onto at low speed. Was considering Strength II Load Combination for strength design with no IM is a reasonable approach in this case, thoughts? Owner is specifying 8000 lb design wheel load intended for light duty pick up truck.

 

[BridgeSmith]

For overweight load evaluation, we remove impact from the loading only if we restrict the the vehicle to 5 mph or less. Not sure if it's in AASHTO (maybe in the MBE).