An upcoming highway ramp closure could cause a few weeks of headaches for Ankeny commuters. The next phase of the Interstate 35/East First Street interchange project in Ankeny requires closing the East First Street entrance ramp to northbound I- 35 beginning Tuesday at 10 p.m., weather permitting, the Iowa Department of Transportation announced. The closure is expected to be in place until early September, according to the Iowa DOT’s Grimes construction office. While the ramp is closed, motorists can follow a marked detour using U.S. 69/Ankeny Boulevard, 36th Street, and I-35. It is likely that while the ramp is closed, there may be traffic backups in this area, DOT officials said.