AADT, ADT and ADTT

[X-Wing]

AADT = Average Annual Daily Traffic
ADT = Average Daily Traffic
ADTT = Annual Average Daily Truck Traffic (is this correct?), practically the data needed in AASHTO

Due to lack of data available (ADTT), can I simply get the ADTT from the AADT, assuming that the variables needed are supposed to be "peak" data that were collected.

There's a table in AASHTO LRFD 2012, Table C3.6.1.4.1 where there is a correlation between ADT and ADTT. The table fairly correlates with the data of AADT that I've got.

Thanks!



Very Truly Yours,

- andru18

 

[ACtrafficengr]

I would be leery about using a heavy vehicle percentage out of a manual without some confirmation. Spending a few hundred dollars on another traffic count could easily prevent much higher costs due to reduced bridge lifespan if you underdesign it.