This paper summarizes results obtained from modeling the network-wide effects in Cambridge of four road-user charging systems: tolls (where vehicles are charged a fixed amount when they cross a cordon); distance-based charging (where vehicles are charged in proportion to the distance travelled within Cambridge); delay-based charging (where vehicles are charged in proportion to delays experienced within Cambridge); and time-based charging (where vehicles are charged in proportion to their travel time within Cambridge). CONTRAM and SATURN were used to obtain the results presented here. Both an inelastic and an elastic demand were considered. The results show that delay-based charging is likely to have by far the best effects on congestion, both within and around Cambridge, and rank the four charging systems in the order: delay-based charging (best), time-based charging, distance-based charging and tolls (worst).