DES MOINES — Northern Iowa motorists traveling through the Des Moines metro area this week should prepare for overnight Interstate 35 closures, including a shutdown lasting up to 15 hours, as construction crews make major traffic adjustments along one of Iowa’s busiest highway corridors.
The Iowa Department of Transportation announced that northbound Interstate 35/eastbound Interstate 80 will be completely closed between the Southwest Mixmaster interchange and Iowa Highway 141 on November 11, 12 and 13, 2026, with an additional closure possible November 14.
The closures could affect motorists traveling north toward Ames, Clear Lake, Mason City and other Northern Iowa communities, particularly those returning from Des Moines or connecting to I-35 from western Iowa.
Construction crews are preparing to shift traffic lanes through the interchange area, requiring full closures while workers establish new pavement markings and complete the traffic reconfiguration.
The Iowa DOT has announced the following closure schedule:
Wednesday, November 11: Northbound I-35/eastbound I-80 will close at 10 p.m. and reopen at 4 a.m. Thursday, November 12. Crews will prepare pavement markings for the upcoming traffic shift.
Thursday, November 12: Another full closure is scheduled from 10 p.m. until 4 a.m. Friday, November 13, to continue preparations.
Friday, November 13: A longer closure will begin at 7 p.m. and continue until 10 a.m. Saturday, November 14, as crews complete the lane reconfiguration.
Saturday, November 14: A backup closure is scheduled from 7 p.m. until 10 a.m. Sunday, November 15, if additional work is necessary.
All closures affect the northbound I-35/eastbound I-80 corridor between the Southwest Mixmaster and the Iowa 141 interchange. They do not represent a statewide shutdown of Interstate 35.
Motorists traveling during the affected hours will need to follow a marked detour.
According to the Iowa DOT, drivers will be directed east onto Interstate 235, then through a detour involving Valley West Drive at Exit 1B, Northwest 100th Street and Northwest Urbandale Drive before reconnecting with eastbound I-80/northbound I-35.
Drivers unfamiliar with the Des Moines metropolitan highway system should watch closely for temporary traffic signs and consider allowing additional travel time.
The closures are particularly relevant to Northern Iowa residents who regularly travel Interstate 35 for business, shopping, medical appointments, college activities and other trips through central Iowa.
Road construction along I-35 has already affected motorists elsewhere in the state this year.
In October, NorthIowaToday.com reported on southbound I-35 ramp closures near Clear Lake as crews completed road repairs.
Earlier in May, northbound Interstate 35 between Ankeny and Ames was scheduled for overnight closures, another project affecting travel between the Des Moines area and Northern Iowa.
The Iowa DOT is reminding motorists to slow down in construction zones, obey temporary signs and posted speed limits, maintain adequate distance between vehicles and remain alert for changing traffic patterns.
Traffic fines for moving violations in Iowa work zones are at least double the normal amount.
Travelers are encouraged to check Iowa 511 at 511ia.org before departing to review current construction restrictions, traffic incidents and road conditions.
Drivers can also dial 511 within Iowa or call 800-288-1047 from elsewhere in the country.
The DOT offers a free Iowa 511 mobile application and optional email or text alerts for motorists who want updates about highway conditions and closures.
More information about the closures is available in the Iowa DOT’s official November 5 construction announcement.
Questions about the project may be directed to Kasi Province at the Iowa DOT’s Grimes construction office at 515-986-2863.
Motorists planning to use northbound Interstate 35 through Des Moines Wednesday through Saturday nights should verify the latest closure schedule before traveling and be prepared to use the posted detour.
