Hundreds of triathletes will be on Reston roads and trails at the Reston Relay Triathlon on Sunday.

While roads will not be closed, some lanes will be blocked, and race officials are warning drivers to be extra careful on the course.

Here is what you need to know:

The race begins Sunday, June 26, 7 a.m. at Lake Newport Pool, 11601 Lake Newport Rd.

Race participants and spectators are asked to park at North Point Village Center nearby.

After the swim portion at Lake Newport, the bike 11.2-mile course will take place on the following roads: Reston Parkway, Wiehle Avenue and Baron Cameron Avenue. See a map of the bike course on the Reston Relay Triathlon website.

The 3.-1-mile run course takes place on pathways, but there will be two north Reston intersections where runners will be crossing: North Village and Center Harbor and at Center Harbor and Wiehle Ave.

Runners are to stay on the right because the first and third miles will have two-way traffic, race officials said.

For more information, visit the Reston Relay Triathlon website.