How do I keep my route on schedule when traffic throws it off?

You can hold the schedule now, and that is real skill. Traffic and heavy stops throw off your whole run because they are the things you cannot control, no matter how sharp you are. That is worth naming plainly. You are not falling short. You are running up against conditions that would break anyone's perfect timing. A schedule is a plan, not a promise the world agreed to keep. When traffic blows it up, the goal shifts from hitting every minute to recovering smart. Do not try to make up all the lost time at once by rushing, because that is where mistakes and burnout live. Absorb the hit, protect the stops that matter most, and let the small slips go. When a run goes sideways, take a breath and ask which one thing most needs to stay on time, then aim there. Let the rest flex. You already have the skill to run to the minute. The next skill is staying calm when the minute is stolen from you, and choosing your recovery instead of chasing a clock you cannot win against.