Commuter rail is a form of rail transit with these characteristics:
- Provides regional transit in place of express bus and stops are further apart compared to light rail or streetcars
- Generally operates on railroad corridors.
- Commuter rail uses larger, faster, and heavier vehicles that can share tracks with freight and intercity passenger trains.
- Trains are operated under railroad rules (set by Federal Railroad Administration) and generally have a conductor onboard the train besides the engineer (train operator).
- Trains may be hauled by locomotives, or have rail cars propelled by diesel engines (DMU), or electric motors (EMU)
- Service levels vary from every 5-10 minutes to every hour. Some systems may just run trains during weekday peak hours in peak directions. Service levels in general are lower than light rail and rapid transit.