For all kinds of reasons, I've sometimes needed a very short haul in a taxi departing an airport/train station where there are long lines (for the cabs to wait in pens for pax) and high fees charged to the drivers.

Some airports such as LGA provide a pass to the driver which allows him to jump the line on his return. But, at others, I simply make it up to the driver in a very nice tip. At SEA where the driver pays $6 to pick you up, I'd simply factor that in as an addition to the tip.

I'm not concerned about whether the driver likes or hates me. I just try to do right by people because I want them to do right by me. (Although my clients tip me poorly !).