- Derailments - you must be able to reach all tracks to remove or to rerail a stalled train. This may include access holes from above, below or side, a removable wall panel, etc.
- Cleaning / Maintenance - you must provide for the ability to clean the rails, pick up debris, etc.
- Troubleshooting - you may have to troubleshoot an electrical short or other problem in which you need access
- Modifications - on occasion you may desire to add turnouts, signals, lights, signs or minor structures.
This takes preplanning, creativity, trial and error. No one has all the answers but recognizing that you may have a need to deal with each one of these issues in the future is the first step to solving them before having to tear things apart.