The Big Half 2026 returned on Sunday, September 6, with more than 25,000 people registered for the 13.1-mile race across four London boroughs. It is a major date in the city calendar, and the scale of the event means runners, spectators and local residents all need to plan ahead.
The half-marathon, which started in 2018, once again used a route from Tower Bridge to Cutty Sark in Greenwich. Elite runners set off at 8:30am, while the main half-marathon began at 8:15am, with road closures in place from 4am.
A city route with wide reach
The course takes in roads across Tower Hamlets, Greenwich, Southwark and Lewisham, which is why the travel impact is felt far beyond the race itself. With more than 25,000 registered participants and almost 400 community groups involved, the event brings a huge number of people into the same part of London on the same morning.
That is also why the source includes travel and access information for spectators, participants, residents and business owners. When roads close at 4am, the effect is not limited to the runners on the start line. It changes how the morning works across the route.
What runners and spectators need to know
The Big Half is built around a simple but striking London route, with Tower Bridge at one end and Cutty Sark at the other. For many participants, that makes the race feel both familiar and special, because it cuts through some of the capital’s best-known areas while still being a fast, flat half-marathon.
The event also includes the New Balance Big Relay and the Big Mile, adding to the sense that this is more than just one race. It is a broad community event, and that is reflected in the number of people taking part and the need to manage access carefully throughout the morning.
For those heading to the race, the key point is timing. With closures from 4am and the race starting at 8:15am, Sunday needed early planning. The Big Half has become a significant London fixture, and on September 6 it again showed how a major road race can shape an entire section of the city for the day.
