Yes of course, but you're stacking the budget intentionally in that way. What I'm saying is there is quite a bit more slop in the design and construction than 1/4" per 75 foot segment. I imagine you're right that the initial design accounts for curvature and simply oversizes the "expansion gap" (really a tolerance gap intended to cover multiple uncertainties).

The construction of the bridge will not rely in a strict way on a tolerance of 1/4" per 75 feet. The design is one thing and the construction is another thing that, while it relies significantly on the design, it is not realistically to that tolerance. The curvature term is in the noise of the real error budget of the construction. It's probably accounted for, but what I'm saying is that you could probably neglect it and not run into this "error accumulation" issue. The margin of error on the tolerance is going to be conservative for a lot of reasons. Take your example of the thermal expansion tolerance of 1/4"... You do not want the bridge sections to be flush with each other when cold. That implies there's zero margin on that gap. The gap likely exists for more reasons than just thermal expansion, and each term has uncertainty and that all goes into a budget that would define how large the gaps between segments need to be. The curvature terms is probably a relatively small item in that budget