Getting a good estimate of elevation is not trivial. Uncorrected GPS-based altitudes used by mapping platforms are thrown off by bridges/overpasses, where terrain and road are on different planes.

From what I understand, bike computers will report altitude based on either barometric sensor (more accurate according to Garmin) or GPS (reportedly accurate at +/- 15 feet). Note that a fairly accurate GPS measurement could result in inflated "total elevation" if readings fluctuate, which is less likely with a barometer.

So... If by route you meant elevation computed by the mapping app, I'd bet that there are bridges.