Estimate toll costs for a route.
Tolls accumulate per gantry or plaza, so the per-trip charge is the number of toll points times the average charge, discounted if you run an electronic tag. Tags matter more than they look: a 15 percent discount on a four-toll route driven twice a day recovers the transponder deposit within weeks, and the annual saving line makes that visible. Cash and video-tolling rates are usually the highest tier, which is what the zero-discount setting represents.
Per trip
Per trip = toll points x average charge x (1 - tag discount)
Rollups
Weekly = per trip x trips per week; annual = weekly x 52
Only when the detour is short. A 15-minute diversion to save 3 in tolls is a poor trade once fuel and your own time are priced, and untolled alternatives are often slower and more congested.
Most networks now bill by plate recognition at a higher rate, sometimes with an administration fee, and unpaid notices escalate quickly. Set the discount to zero to see that worst case.