Heathrow has finally started swapping out the little driverless trains that ferry you between the T5 satellites, and the upgrade to the Heathrow Terminal 5 transit is a bigger deal than the airport’s own breezy blog post lets on. The trouble is, that blog skips every number worth knowing. It talks up a ‘smoother, more reliable’ shuttle and 20 shiny new vehicles, then carefully avoids telling you what any of it means for the people standing on the platform. So we did the digging.
What the Heathrow Terminal 5 Transit Upgrade Changes
The current setup is a simple back-and-forth. Two trains run the 700m route, one on either side of the platform, departing roughly every 90 seconds at up to 31 mph. Trip time is 45 seconds to T5B and just under 90 seconds to T5C. On paper the system shifts up to 6,500 passengers per hour in each direction, which sounds generous until you’ve stood shoulder to shoulder on that platform at 07:00 with half a 777’s worth of connecting passengers.
The fix is simple: more trains, more often. Heathrow is going from two trains to four, with each train formed of four cars, doubling the frequency on the route. You can’t run four trains as a simple shuttle on two tracks, so the pattern changes as well. Instead of the old back-and-forth line, the trains will run as a figure-of-eight layout that Heathrow keeps mentioning without quite explaining.
Across the whole programme, 10 older cars at the end of their working lives leave service, while 10 more expand the fleet, taking the total to 20. Each car is a 15-tonne machine, lowered into the tunnel overnight through a sliding roof, with about 50cm of clearance and a 10mm tolerance against the electrified guideway. Fiddly work, then, and a fairly obvious reason this has dragged on for years.
No more queueing for the 5B train?
The big story here is capacity. With roughly twice as many trains running twice as often, passenger flow should climb from about 6,500 people per hour, per direction, to around 12,000 to 13,000. Twice the frequency also means shorter waits, so that early-morning crush should ease considerably once the full fleet runs.
Terminal 5 is busier than ever, and Heathrow’s growth plans will only push numbers higher. If you’ve ever sprinted off a long-haul arrival hoping to reach the Galleries Lounge in T5B before a tight connection, you’ll know the old shuttle was a real pinch point. A faster, more frequent Heathrow Terminal 5 transit should take some stress out of those marginal connections, especially with passenger numbers set to keep rising well before any third runway appears.
The Caveats Worth Flagging
Two caveats are worth keeping in mind. First, Heathrow hasn’t published an exact new passengers-per-hour figure, so ‘roughly double’ is a sensible extrapolation from the fleet size and frequency, not an official headline number.
Second, the project runs until mid-2026, so you won’t see the full benefit on every visit just yet. Heathrow is installing the new cars overnight, a handful at a time, while the old ones still do most of the hard work.
Still, this is one of those unglamorous infrastructure upgrades that quietly makes flying out of T5 less of a faff. The Heathrow Terminal 5 transit system was overdue a refresh, and doubling capacity is exactly the right fix. Our tip: if you’re connecting through the satellites on a tight margin during the works, allow an extra 10 minutes until the full fleet is running.
Read: Will Heathrow Ever Expand? The Runway That Refuses to Take Off.
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