On Sunday May 19 the biggest half marathon in Australia, the Sydney Morning Herald Half Marathon, will see almost 12,000 runners pounding the inner-city pavement. In other words, Sydney’s streets will be affected.

While the 21.1-kilometre race kicks off at 6.45am, road closures will begin from 4am and end at 11.30am. The Cahill Expressway over Circular Quay will be closed from 4am until 11am, meaning motorists travelling towards the city via the Cahill Expressway won’t be able to exit onto Macquarie Street. Instead, they’ll be diverted through the city via York Street.

Sections of the Western Distributor, including the on-ramps and off-ramps, will be closed from 4am to 10.30am. Drivers travelling into the city on the Anzac Bridge will be diverted via the Bathurst Street off-ramp.

Sections of College Street and Macquarie Street will be closed from 4am until 11am, and Art Gallery Road and Mrs Macquaries Road in the Domain will be closed until 11.30am. Around The Rocks and Circular Quay, sections of Bridge Street, Alfred Street, Pitt Street, Young Street, Loftus Street, George Street, Harrington Street and Hickson Road will be closed between 5am and 8.30am.

Sussex Street, Kent Street, Pottinger Street, Windmill Street and Watson Road around Millers Point and Barangaroo will be shut between 5am and 10.30am. And from 4am to 10.30am, Pyrmont Street, Pirrama Road, Bowman Street and Darling Drive will be closed in Pyrmont and Ultimo.

Special event clearways will be in place along the route and in surrounding streets between 3am and 10.30am.

For those donning their runners on Sunday, the best way to get to the start line on College Street (next to St Mary’s Cathedral) is to catch public transport. St James, Martin Place and Town Hall stations are all within walking distance and trains will be running to a regular Sunday schedule.

Trackwork on the T1 North Shore line means trains on that line will terminate at Wynyard. Trains on the City Circle line will run in only one direction from Central, with the first stop Town Hall.

Extra buses will run into the city from Mosman, Coogee, La Perouse and Maroubra, from 5am. The nearest car parks are the Domain and Enacon car parks, and Wilson car parks at Riley and Liverpool streets.

The Sydney Morning Herald Half Marathon starts at 6.45 am on Sunday May 19. Find out more and download a road-closure map here.