The marathon officially starts at 7am on Sunday January 18 and the course closes at 1pm. In the past, walkers say they have been allowed to start two hours early, but this year, directors say if the 600 or so walkers can't make it across the finish line when the clock hits 6 hours, they can't participate.
"All the way back to 1999 when Methodist, I think, was the sponsor," said marathon walker Joy Stapp, showing us one of her nine medals for finishing.
And Stapp is hoping they won't be her last.
"I registered in January because I wanted my place. I wanted to do number 10," she said.
But this year, the marathon is cracking down on its time standards, mandating all participants finish within the allotted time.
"I won't be able to finish it in 6 hours, I mean, I wish I could," said Stapp.
Houston Fit, a group that trains runners and walkers, says for several years, slower participants have been allowed to start at 4:30 or 5am, so they can finish before the course closes.
"We have our own security. They never walked with chips and they didn't have anything to do or compromise numbers of the statistics," said Debbie Mercer, director of USA Fit.
But the marathon director says the early start time is dangerous because the roads aren't closed until 7am.
"It's also effecting 18,000 other participants who eventually come up on the backs of these walkers," said Race Director Steve Karpas.
"In the street, we stay to the right, far to right, never more than two abreast and we just stay out of way of runners," said Stapp.
We caught up with some marathoners who gave their opinion.
"I've never had problem with walkers," said Allen Webb, who's run the Houston Marathon 13 times. "I think they should encourage walkers."
"I think you lose your concentration to a certain extent, especially where people are crowded together," said marathon runner Joseph Nabors.
"I don't see where safety would be that much of an issue at 4:30 in the morning," added marathoner Jo Tucker. "There's not that much traffic to begin with."
Meanwhile, walkers say giving them a two-hour head start is so important because no matter how long it takes them, it's such an accomplishment.
"Crossing that finish line has opened up a whole new world to me," said Hugh Fraser, who walks the marathon.
Fraser, 61, finished his first marathon last year and lost 55 pounds during training. He can finish within the 6 hour time limit. As for Stapp, she's determined to go on with or without a medal.
"I may be finishing it late. I may be out there on the sidewalk with the traffic whizzing on by me," she said.
Houston Fit says they are willing to work with the marathon by providing their own security early in the morning. However, the director says if you have already registered and know you can't finish, you can still get a partial refund.
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