The south side of Dublin city will be a no-go area for motorists for most of next Monday as 40,000 women runners take to the streets for the 23th Women's Mini Marathon.
The race starts on Merrion Square at 3pm, and the majority of participants are expected to finish by 6.30pm.
However, most of the streets along the 10km route will be closed from early on Monday morning.
"We will be endeavouring to open the roads as soon as the participants pass through, for example, we expect to reopen Fitzwilliam Square at 4.30pm, a spokesman for the race said.
"But areas like St Stephen's Green will be closed from 6am to 6.30pm."
Participants will be following a traditional route from St Stephen's Green out to the Stillorgan Road and back.
However, new finishing point has been designated at Earlsfort Terrace to avoid taking runners into the Luas terminus.
Another new aspect of the race is the "champion chip" device, which gives participants the option of monitoring their time and finishing position.
A small transmitter is attached to the shoe laces of participants. The transmitter is activated when the runners pass over a special mat at the start of the race.
When the runners pass a similar mat at the finish line, their place and time are accurately recorded.
Just over 4,500 participants have chosen to use the chip, the spokeswoman said.
"We're delighted that so many people took it up, and we're looking forward to seeing how popular it will be next year."
Roads affected by the mini marathon are:
Merrion Square at 3pm, and then Lower Mount Street, Mount Street Bridge, Northumberland Road, Pembroke Road, Merrion Road, Nutley Lane, Stillorgan Road, Donnybrook, Morehampton Road, Leeson Street, Leeson Street Bridge, finishing up at Earlsfort Terrace.
