Does it really matter if I use trackbed with HO model railroad tracks (Code 100)?

well roadbed is nice. gives you a base to not only lay track, but also to give a shape to ballasting it. however it is totally not required. ive always used Atlas roadbed and never had a problem with it. as far as your bridge goes youll want to end the roadbed. i wouldnt carry it across the bridge. it wouldnt look right and in most cases ( depending on the type of bridge ) you wouldnt need it. a stone arch would use it as opposed to an open girder type which wouldnt. actually some real bridges you can see right thru the tracks down below. remember, its not the ballast that supports the track. as bridges prove. its the roadbed under the ballast. but in model railroading that support is not required at all. its mostly for sound deadening and looks. somefolks actually lay track right on homasote or other soft sound deadening media.

Good trackwork is the foundation of a happy model railroad . Take your time , and spare no expense in the construction of your track. Nothing is more frusterating than poor trackwork . Use flex track ,rather than sectional track. A good base to start with is a fiber material such as tentest or homeasote . I use cork roadbed on the homeasote to model the main line track , and lay the yard and industrial sidings directly on the homeasote .

Buy books before you start. Atlas has a good , "How to" series of books to get you started. As far as one product being better than another? I've found that roadbed products are all about the same. As for the bridge, both ways work