Cost per vehicle is not enough to compare trips with different load sizes and stop counts. When preparing a set-menu quotation, relate transport expenses to the same period and the number of portions delivered.
Build an expense table for one period
Record fuel, driver and loading labour, waiting time, vehicle use, container washing and damage costs over the same period. If you allocate depreciation or replacement cost, state the method; do not charge the purchase price again in every period.
Calculate cost per portion
Divide period expenses by portions delivered and accepted during that period. Show returns, redelivery, waiting and missing containers separately. Do not add the sales value of rejected food as if it were a cost; use documented extra work and material loss.
Start with data from several representative service days and compare busy and low-volume days separately. For each new quotation, state assumptions about load factor, stops and returns so actual results can later be reconciled.