Recently in my Pathfinder campaign, I have had two sessions where most of the action was running and flying to reach a single enemy. Two months ago, the party tried to sneak up at midnight on a sorceress living in a tent surrounded by low-level minions. The sentries spotted the party 500 feet out (a few PCs had terrible stealth), so they switched to running toward the sorceress while throwing long-range spells. In this week's session, the party had taken out intellect devourers and other eldritch horrors hiding on a farm, but one cultist possessed by an intellect devourer ran away and the party did not chase after him until they defeated the others. This chase lasted a full mile, with the intellect devourer and two party members using Dimension Door as a shortcut.
The party members have different speeds, so the party becomes strung out when each individual moves as fast as possible in the chase. When one or two party members catch up to their opponent, the rest of the party is left out of the action. And Dimension Door often means that someone who rushed ahead is left behind, instead.
Furthermore, the chases takes more time than combat itself. The mile-long chase took 2 hours in real time. Is there any way to speed it up?
When I tried handwaving the details of exact locations, the players insisted on exact arrival times. I ended up tracking and reporting locations in detail: "You are 120 feet from the start, so you have 380 feet to go. If you keep running at 120 feet per round, that will be 4 rounds." Imagine updating that detail every round, after the player says, "No, I am not running. I cast a fireball instead, and then I move 30 feet. Wait, maybe I should run."
I also tried laying out the minatures in a not-to-scale line with distance written beside them on the playmat, and that helped. But even with the compressed scale, the minatures ran off the playmat. Any other suggestions?
There are some nice options for chase scenes in the game mastery guide.
I used similar options once in a Rise of the Runelords campaign. Those options help give details to a short chase to make it feel like covering actual terrain, instead of a bland system of distances.
I am after the opposite. The bland system of distances is too much detail in a mile-long chase. I don't have time to mention the scenery, I don't have time to interact with the terrain. When the chase started with the intellect devourer half a mile away, I tried to invoke the overland travel rules, but the players wanted round-by-round details instead. At least I avoided rolling for initiative until they caught up to the intellect devourer.
The chase cards mentioned in the Game Mastery Guide might adapt to a mile-long chase. I could keep a set of 3x5 cards at the game table, put one under each minature to indicate locations, and maybe two or three extra cards to denote landmarks or obstacles. Those could show progress without going off the end of the table, as with the playmat.