Air carrier Captain describes the the intersection of Taxiways D and C at DAL as confusing at night and suggests that flashing amber lights be built into the concrete to denote the hold line for Runway 31L.

Narrative

While taxiing from the gate to [Runway] 31L for departure; we were instructed to taxi via D to C to 31L. It was dark; but excellent visibility. While taxiing southwest on D; there were green lights on the yellow line that I was following. Approaching C; I could see where the green lights made the left turn toward 31L; but the green lights also continued straight ahead across 31L and continued past the runway. I was momentarily confused (even though I had flown into and out of this airport for more than five years as a First Officer); because all I could really see were the green taxi lights. I couldn't see any runway lighting as I was approaching C and 31L. Part of the reason I couldn't see any runway lights is because the taxi area where D crosses 31L on the east side is very wide due to it being a 'semi' high speed exit from 31L. From my perspective looking southwest; all I could see was a wide dark area with the green taxi lights extending through it. I did notice there were runway ID signs at either end of the large dark area; but they didn't look very bright (maybe some of the lights were burnt out) or maybe the fact they were so far apart they just weren't noticeable. I made the turn southeast onto C and realized it would have been nice to have the flashing amber lights built into the concrete (like we have on many other airports) and some wig wag lights too. This would better alert our crew that they are approaching an active and heavily used runway. I called Ground Control and tried to explain how the lighting was a little confusing to me; but didn't have much luck explaining it to him. I know that runway incursions are a high priority with the NTSB; FAA; and our company so wanted to bring this to your attention. Is there any way we could improve the runway lighting in this area?