Circuitron has an auto reverser (AR-1) that can be used on DC systems only. I have no experience with it but for those still using DC it may be the solution you are looking for.

DCC has a number of options for dealing with this issue. The basic method is the same as for DC (DPDT switch). There are also electronic solutions of which the AR1 from Digitrax is one. This works adequately in most cases but is “old” technology. They use a mechanical relay to switch polarity. It works but it is slow and DCC is very sensitive to shorts. To use an AR1 on a DCC system you generally have to reduce the speed which the system or breakers shut down if there is a short.

This allows you to go through the reversing loop and come out the other side without your DCC system shutting down. You may here a click as the polarity is thrown if you are running quiet. Unfortunately all your decoders are experiencing the short and overtime the electronics of the decoders will not react well to this shorting. The better route to go is with a solid state auto reverser, they will sense a short and flip the polarity quicker than the DCC system will sense the short and reduce the risk of damage to your other decoders.

No Bill. Just change the polarity of the block the train will be going into when it comes out of the reversing section. No stopping of train required but you must be paying attention so that the polarity is the same when it comes out of the reversing section as to what it had at the end of the section. Sounds basic but it is just a matter of time until you forget and you have a short.

Won’t the Loco go into reverse if you switch polarity while it’s still moving!

Yes, but while the train is in the loop you need to simultaneously through the DPDT AND the reverse switch on the power source to then align the rail polarity for the train to exit the loop.