During a layover, transport is not about the cheapest option. It is about the one that gets you back on time, with a fallback if it fails.
That usually means a rail link or a frequent express bus, both of which are immune to traffic in a way taxis are not.
Compare on frequency, not just speed
A train every ten minutes that takes thirty five minutes is better than a bus every hour that takes twenty five. If you miss one, the next is right behind it.
Also check the last service in each direction. Layover excursions go wrong at the return end, particularly late in the evening.
Step by step
Step 1: Start at the airport transport page
It lists every service with times and prices, and it is more accurate than general map apps for airport specific routes. Note where each service departs from, terminals often have separate stands.
Step 2: Buy a return where possible
Return tickets on airport express services are often discounted and save you queueing at a machine when you are in a hurry. Keep the ticket somewhere you will not lose it.
Step 3: Save an offline map and the return timetable
Roaming can fail, and airport wifi does not follow you into town. A screenshot of the timetable and the walking route to the station takes ten seconds and removes a lot of stress.
Step 4: Set a hard turnaround time
Decide the moment you must be on the return service, set an alarm, and treat it as fixed. If you are running late, a taxi is the emergency option, so keep enough money or a working ride hailing app for that.
