Boise Police Department
News Release

William L. Bones
Chief of Police

Contact: BPD Media Relations Office


Friday, June 11, 2010

Traffic Alert - Road Closures due to Ironman Triathlon

061112 Traffic Alert - Road Closures due to Ironman Triathlon

The following is courtesy of the Ada County Highway Distric

Major impacts to drivers expected during Boise's Ironman event

           Over the course of eight hours, participants in Ironman Boise 70.3 will race through town as they complete a 1.2-mile swim, 56-mile bike ride and 13.1-mile run in succession. This year's Ironman Boise will start on Saturday, June 12, 2010 at 2 p.m. beginning at Lucky Peak Reservoir and end in downtown Boise on 8th Street in BoDo.

           1,400 participants are expected for this event. This is the third year of a five-year agreement between the Ironman organizers and the city of Boise. Course maps and information about the event are available on the Ironman Boise Web site:  The maps are also attached to this email.

           The Ada County Highway District (ACHD) is working with Boise City, Ironman organizers, Boise Police, the Ada County Sheriff's Office, the Idaho Transportation Department (ITD) and others to prepare for the road closures necessary to make the event possible. Citizens not involved in the Ironman event are urged to prepare and take alternate routes. Detour routes will be in place for the closures and drivers should use caution.  Boise Police officers will be stationed along the course and will help residents get in and out of businesses and residences during the event. There will be around 75 flaggers directing traffic and 45 volunteers will also help along the route at intersections and driveways.  

            ITD is planning a different approach to restrictions on Idaho 21, which is used for the cycling portion of the event. Idaho 21 has been completely closed in the cycling area in years past, but this year one lane will be maintained for traffic to get through in both directions. There are no "hard" or complete closures planned without detour routes in place.


Idaho 21 on Saturday, June 12

.         2:15 p.m. - Flaggers will start directing traffic between Diversion Dam and Surprise Way, and lane restrictions will be put in place.

·         Between Diversion Dam and Lucky Peak Dam, the right northbound lane and shoulder will be closed off to traffic.  One northbound lane will remain open to traffic, as well as both           southbound lanes. 

·         Between Surprise Way and Technology Lane one lane in each direction will be maintained.

·         7:30 p.m. - Based on past years, the last bicyclist is anticipated to move through by this time. Traffic flagging will end as soon as the last rider leaves Idaho 21.

·         7:45 p.m. - The highway returns to normal operations.  


Other ITD roads impacted Saturday, June 12


·         Noon - Front Street will close between 6th and 9th streets.  Traffic will be detoured north on Capitol, west on Idaho, south on 9th back to Front. This area will be the first-aid medical station and the command center for law enforcement during the event.

·         Between 2:40 p.m. and 7 p.m. the I-84 Eisenman interchange ramps will be closed and traffic will be detoured to the Gowen interchange.  The closure of the Eisenman interchange allows the bicycling portion of the competition to be rerouted away from the Gowen interchange and the Idaho 21/Federal Way intersection, which are more heavily used by motorists.  The interchange is expected to reopen as soon as the last cyclist gets through the area.

·         4 p.m. - Myrtle Street will close between Capitol Boulevard and 9th Street.  Traffic will be detoured north on 11th, east on Main Street, south on 3rd back to Myrtle.

·         11 p.m. - Myrtle Street will return to normal operations.

·         After midnight - Front Street will return to normal operations.


ACHD roads impacted include:

Full closures


·         8th Street between Broad Street and Front Street closed Thursday, June 10 (today) at 8 a.m. and will be back open Sunday at 8 a.m.

·         Capitol Boulevard between Myrtle Street and Front Street will be closed Friday, June 11 from 6 p.m. to Sunday, June 13 at 12:30 a.m.

·         Broad Street between Capitol Boulevard and 9th Street will be closed between 4:30 p.m. and 12:30 a.m. Saturday.

·         Pleasant Valley Road from Gowen Road to Ten Mile Creek Road will be closed from 3 p.m. to 6:45 p.m. Saturday.

·         Ten Mile Creek Road will be closed from Pleasant Valley Road to South Cole Road from 3:20 p.m. to 6:30 p.m. Saturday.

·         Eisenman Road from Interstate 84 to the Boise Factory Outlets mall will be closed from 2:50 p.m. to 6:45 p.m. Saturday.

·         Federal Way and Capitol Boulevard will be closed between Protest Road and Myrtle Street from 4:30 p.m. to 8:20 p.m. Saturday.


Lane restrictions


·         Warm Springs Avenue between Highway 21 to the ParkCenter Bridge will have a lane restriction and delays between 4 p.m. and 7:40 p.m. Saturday.  Only northbound traffic will be allowed between Highway 21 and the Idaho Shakespeare Festival.  The Shakespeare Festival will be accessible from town, but expect detours and delays.

·         Gowen Road between Eisenman Road and Pleasant Valley will be westbound traffic only between 2:50 p.m. and 6:45 p.m. Saturday.

·         Holcomb/Bergeson between Boise Avenue and Federal Way will only be open to eastbound traffic from 4:15 p.m. to 8 p.m. Saturday.

               ACHD will have special traffic signal timing plans for the closures on Capitol, Front and Myrtle to help move traffic.  An ACHD traffic operations engineer will be at the ACHD Traffic Management Center Saturday monitoring traffic conditions and adjusting signals if needed.

           Reader boards on local highways and the Connector are in place to alert motorists to the closures.  Ironman organizers distributed 5600 mailers describing traffic impacts to residents.

           As a public service, ACHD provides information about lane restrictions and closures for both ACHD and non-ACHD projects and events.  A map of all road work taking place in Ada County, as well as more information on this project can be found at