On Time Running Updates

I am developing an app and one of the things I want to show is the on time running updates to the user (eg show that a bus is running 2 mins late or on time etc) I am looking at the data returned by the [Public Transport - Realtime Trip Update] api but looks like the “delay” here is really an update after every bus stop.

Is there another API elsewhere that has the data I am looking for because if a bus is doing a long trip say on the M2, that’s about 30 mins travel without any bus stops so the “delay” won’t be very useful to me.