Big discovery. Added the variable a$Traffic. This is based on IntAADT and will replace the TotalT5YrInM (based on AADT). This new variable Traffic is a great offset as the accidents are strongly and linearly related to it.
Updated the formulas to include the new variable Traffic. Use this as offset instead of TotalT5YrInM since it is better related to number of accidents.

This will make a big difference to the model results.