Organizers are preparing for the 40th annual Nationwide Children's Hospital Columbus Marathon and 1/2 Marathon, which will start early Sunday morning in the North Bank area of the Arena District. But motorists and COTA passengers will start seeing road closures and bus route changes beginning Thursday.

Numerous road closures and hundreds of changes to COTA bus routes will start Thursday and Friday, as the city prepares for the Nationwide Children's Hospital Columbus Marathon and 1/2 Marathon.

The route for the Sunday event will remain essentially the same as last year, but organizers have added a few new touches in celebration of the marathon's 40th anniversary, Race Director Darris Blackford said.

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At Mile 16, on the Ohio State University campus, a large video display board will show short videos made by friends, families and other supporters to encourage runners.

"People are really getting into it, which is great," Blackford said. "It can be from a child, a spouse — whoever wants to leave a message."

At Mile 20, traditionally a point at which runners are about out of gas and feel as if they've hit "the wall," there will be a "Storm the Wall" display with people dressed in medieval costumes.

Blackford said the aim is to enhance the back half of the 26.2-mile course in light of the anniversary. "It's still a big-time qualifier for the Boston (Marathon), but we wanted to make it a little more fun."

Less fun will be the effects on traffic in the North Bank Park area of the Arena District, and the bus service disruptions, a given considering the length of the course and the logistics. The marathon draws nearly 18,000 athletes from 45 states, along with approximately 100,000 spectators.

The Central Ohio Transit Authority said rerouting of some bus service will begin after the morning commute Friday, continue Saturday and broaden at 4 a.m. Sunday, when more than 500 bus stops will be closed Downtown, in the North Bank area, University District, Short North, Upper Arlington and elsewhere. Significant delays are expected; for more information go to cota.com/news/columbus-marathon or call 614-228-1776.

Rolling road closures will start at 9:30 a.m. Thursday, when Long Street will close between Neil Avenue and Hocking Street. Two lanes will reopen from 6 a.m. to 9:30 a.m. Friday; after that, Long from Marconi Boulevard to Hocking will close for the weekend.

Also starting at 11 p.m. Friday, Spring Street will be closed from West Street to Hocking; Neil will be closed south of New Public Way to the combined start/finish line at Long Street in the North Bank area.

On Saturday, Spring Street will reopen from 3 to 11 p.m. for the Blue Jackets' home game, then close again after that until 6 p.m. Sunday.

The race will start at 7:30 a.m. Sunday on Long Street. Roads will be subject to partial or full closure based on expected arrival times of the first and last athletes. Spring, Long and Neil will reopen at 6 p.m. Sunday.

For more information, go to www.columbusmarathon.com.

rprice@dispatch.com

@RitaPrice