Drivers are being reminded to use caution Sunday with more than 100 athletes set to make their way along the Alaska Highway and Hamilton Boulevard as part of the city's 12th annual triathlon, beginning at 8:30 a.m.

"This Sunday, the city is set to continue its tradition of hosting one of the most challenging sporting events out there and I'd like to wish all the participants the best of luck,” Mayor Bev Buckway said in a statement earlier this week. "I'd like to remind all motorists to pay attention to signage and use extra caution on the race route so we can be sure to have a good event.”

Competitors in both the Olympic and Sprint categories will begin their races with the swimming portion of the event - with Olympic swimmers doing 1,500 metres, or 60 laps, in the pool at the Canada Games Centre and the Sprint swimmers doing 500 m or 20 laps.

Competitors will then hop on their bikes for the next portion of the race.

"The cycling route is new this year,” leisure program coordinator Kathy Zrum said, noting the city is making use of the Hamilton Boulevard extension.

From the Canada Games Centre, cyclists will head down Sumanik Drive and then along the Alaska Highway to Robert Service Way where they will head up the Hamilton Boulevard extension back towards the Canada Games Centre.

Those in the Sprint category will do the circuit twice for a total of close to 25 kilometres, while those in the Olympic category will go around three times or 40 km.

In the past the cycling route for the triathlon has been out towards Mount Sima Road and, last year, was around Miles Canyon.

"That's a tough one,” Zrum said of the Miles Canyon route, adding the new circuit offers some challenging hills while also having a "nice, wide shoulder” on the extension for cyclists.

It also means competitors stay within the same central area for the entire race.

Finally, those in the triathlon will use their own footpower for the final part of the race.

Those in the Olympic category will run 10 kilometres along the asphalt then gravel path along Hamilton Boulevard to North Star Drive and back to the Canada Games Centre.

Sprinters, meanwhile, will run five km along the same path. They will turn around though at the Hamilton Boulevard pump station rather than continuing on to North Star, Zrum said.

With 54 individuals and five teams, numbers are down in the Sprint category by a bit, but up in the Olympic category which has 36 individuals and 11 teams.

As Zrum pointed out though, many familiar names that were in the Sprint category of past years are now in the Olympic category for this year's race.

"There's definitely a big, common group,” she said of the those who continue to return to the city's annual event.

"It gives a lot of people something to train for,” Zrum said, noting the discussions she's had over the years with returning triathletes who want something to focus on for the coming season.

Others use it as a "good warm up” to the annual Kluane Chilkat International Bike Relay from Haines Junction and Haines, Alaska.

And still for others, it's a chance to compete in one of just two triathlons which happen in the city every year. The other, held later in the summer, is run by another organization.

Given the numbers it now has, Zrum said the only way the city could add a participant is if another drops out.

The first swimmers will hit the water at 8:30 a.m. with organizers having a staged start that allows for the slower racers to start sooner with the last competitors to start at noon.

It's expected the final competitors will finish at about 2 p.m.

On hand throughout the race will be numerous volunteers with the Whitehorse Glacier Bears doing lap counts for the swimmers, ski patrol providing first aid assistance and Katimavik volunteers helping out in various capacities.

"We're very grateful to all the volunteers and organizations that help make this event so successful,” Zrum said.