In the old days a road bike took fenders, wider tires and was made of steel. The reasons had to do with poor roads and bad weather, which most of us still come across. Road bikes nowadays are geared for racers*, and not for duffers or tourists like me. If you want a bike to commute on, randonneur on, or tour on: you don't want a racing bike, because you can't build it well for all conditions; you don't need an overbuilt touring bike, because it will encourage you to carry too much baggage: you need a CX bike**, or something much like it.
Yes, I know you could get a hand-built bike for randonneuring, or you could get a semi-custom build-up from a good local bike shop, Rivendell or Velo-Orange or such... but who has that kind of money for each of several bikes they have. Besides, you're not reading my advice if you are in that deep. This is advice for people like me who want to pay the least for the most, and get a bike they won't regret paying for. You want canti-brakes, because you can fit any tire under them, with fenders. You want steel, because it is the cheapest way to get a comfortably riding frame. You want geometry a touch more relaxed than a modern racing bike, but not so slow as a touring bike. You don't want a carbon fork, because you cannot modify or attach anything to it. You may want rack braze-ons, though I have eschewed racks for frame bags, seat bags and a handlebar bag mounted off my steerer with a strong (aluminum) accessory holder.
I prefer fixed-gear for commuting, because I do not like to have to shift in traffic, among other reasons. Here are some options:
Fuji Feather CX
All~City Nature Boy
Sometimes you need gears after all. Here are those options:
Gary Fisher Lane
Masi CX Uno
Salsa Casseroll (actually a rando bike)
Surly Cross Check
All~City Space Horse (also rando?)
You take any one of these bikes, strip off the chain-guard/bash-ring, throw on fenders and 28mm road tires, and you have a great all-purpose road bike. Take off the fenders and put the cyclocross tires back on and you can race in that, if that's your idea of fun. Use the fenders and as wide a tire as you can under them, and you have a third-world road touring bike.
For some real travel fun, you could get the Dahon Tournado, with a Richey Break Away frame, but I think it's a bit overbuilt; for about the same you could build up your own ride around a Ritchey Break Away Cross frame. As the Break Away, or S&S coupler, premium is $500+, you have to ask yourself how many airline bicycle-baggage-fees you're likely to save. This is not a quick folder for commuting.
*Literally over-geared, and on compact-double cranks impossible to decrease without a change-out: the easier way is a bigger cassette. Some have a high bottom-bracket, moving your point of balance higher than you want: most don't.