Does anyone know if the load times are longer on dreamcast than pc? i think so but i'm not sure so i would like to know what other people think

I think so, I noticed this when I was verifying some runs. I think the PC version saves a few seconds from loading overall but I haven't timed it properly so i'm not completely sure. Interesting difference if that's the case.

if that's the case what do you think about using just the lap times from the time attacks by putting them together and organize the leaderboard using that?

I didnt time loads either but in my experience Dreamcasts tend to load very slowly especially compared to PCs, so I probably have a disadvantage. But honestly I don't mind keeping RTA

ingame time would fix the load time differences between Dreamcast and PC and also between different PCs. The downsides to ingame time are it ignores all menuing (which honestly I would argue is at least to some degree part of the run) and it's less accessible. For a very short category like Driver's Test, ingame time might work. But if there are any plans for like full game runs or something that take much longer, IGT seems unreasonable to me, not only cause it would be a huge pain to calculate, but also because a long full game run would have more emphasis on menuing and routing which would not be accounted for by ingame time.

if IGT doesn't work what about making different sub-categories for dreamcast and for pc?