When the state built MARCS, it placed enough towers in each county so that OSP and ODOT could, most of the time, hit a tower with an in-vehicle radio. They were not exactly concerned with local police and fire departments hitting a tower with portables far off state routes or within buildings. Simulcast solves this. When built, the infrastructure for simulcast has been paid for by the county. The three in my area: Summit, Stark, and Tuscarawas were already faced at the time with replacing outdated analog and/or mixed mode trunking systems.