DC/DCC

When it comes to insulating joints around switches, etc.  DCC and DC are exactly the same.  If you need gaps in DCC you need gaps in DC, if you need gaps in DC you need gaps in DCC.

No

Other than standard frog insulation and the potential for block gaps there is no need for gaps in a single crossover.

Terry

Crossover Gapping

... UNLESS you're using "power-routing" switches, which selectively power the route for which the switch is lined. Two of those facing frog-end to frog-end will cause a short if not both thrown for the same route. The "dead" route actually has both rails set to the same polarity, so if one switch is set for its main track, and the other is lined for the crossover, the reversed switch lines power down its rails and causes a short on one of the rails, where opposite polarities are now meeting.

If the switches are non-selective power routing, (the frog is jumpered so that both routes are fully powered all the time and the position of the switch doesn't matter) then there's no problem.

Right

Chris is right--I normally throw both switches in a crossover at the same time and that is the basis for my reply.  I didn't cover all possibilities.

Terry