I concur with Bob. I have run battery powered O gauge locomotives using DCC on the floor with no track at all using the AirWire system. The system sends a DCC signal from a handheld remote to a receiver in the engine and then to the DCC board. The engine power comes from the battery. You get all the usual DCC features. It is an expensive conversion (about $300) but it works.
DCS does require the track signal now. I don't know of any DCS compatible radio transmitters / receivers that will bypass the TIU and send a signal directly to / from an engine. You can, however, use the AirWire system to control a MTH PS-3 engine by connecting the AirWire DCC receiver to the PS-3 DCC board. This can be done with or without a battery. NH Joe
This is all good info, I didn't know about the AirWire system. I wonder if Lionel TMCC/Legacy engines would work out of the box since their system is already radio based.
That said, converting all of my motive power to use batteries, charging the batteries, and finding two rail track that works with high-rail wheelsets seems like a lot of extra work, extra cost, and doesn't really cover the gist of this post.
The motivation behind discussing stud rail for O gauge is the potential upcoming loss of ScaleTrax, which to my eye looks the most realistic of all the 3 rail options and is pretty price competitive. I watched Rich Battista's videos and then bought a small sample of ScaleTrax. After experimenting and using his techniques, I found it a dream to work with. Staggering the start of the rails from flex-track piece to flex-track piece results in wonderful curves and is so easy to work with.
I'm really lamenting the loss of ScaleTrax and I'm unable to find a dealer to supply all of the track I need for my planned layout. Obviously Gar-Graves and Atlas are great options, but I dislike the height of Gar-Graves and thick center rail, and I'm not crazy about the rail joiners on the Atlas product. Don't get me wrong, they're great products, but out of the box ScaleTrax just looked and worked great for my needs.
I'm really hoping that someone picks up the line after MTH is dissolved or someone offers a stud rail track that looks more prototypical and keeps some of the great features that the MTH product had.