[firebug]

Well if the players know their target, they'll do a lot more than just chase him/her on foot.  If the players do the legwork necessary to learn the powers of this adept, they should ambush the adept in such a way that escape is nearly impossible.  Putting the adept into a closed-off building would work, per the example I gave.  But also using drones and vehicles as necessary to "outrun" the adept would allow the players to nullify the target's advantage.  I mean, legwork is half the game for a reason: forewarned is forearmed.

Part of the difficulty of this job is that they will have to do most of their own legwork, due to the target being "new".  The hook is that the adept was creating rumors in the corridor while he was purchasing supplies (and moving between a lot of stores so his radiation didn't have time to become too noticable) but ended up leaving a trail anyways (he's not that skilled at such things).

Ideally they try to learn his patterns without alerting him, because going straight for him won't work.  Mind, the players are relatively new to Shadowrun and the characters aren't terribly experience bounty hunters either.

But until that point, they have little way to properly corner him.  The chase rules are just needed to show them that a brute force approach won't help them, since they're trying to find one man who leaves little signature in what's essentially his home field.

[Namikaze]

Gotcha - that makes a lot of sense then.  Hopefully this will give the players some incentive to find an alternate approach then.  Ideally one where they can control more of the variables.  For a new team, it makes a lot of sense to give them some education in the school of hard knocks. 

[The Wyrm Ouroboros]

Also, don't forget line-of-sight.  If a person being chased can break LOS, and get into and/or through an area where LOS is broken quickly, then it can become a matter of a stealth vs. perception roll, with a bonus to the pursued for how far ahead they are.  This can represent 'he's quite a bit ahead of you when he goes into the marketplace.  When you get there, you can see him up a ways - then he goes between two booths.  Pushing up to where you saw him go in, you take a look around, but there's a lot of different places he could have gone.  Looks like he got away.'

Going into the Cermak Rad Zone is going to be similar; there were buildings there, and some/many of them are probably still relatively intact.  Going into a maze like that ...