A major highway ramp closure is set to impact commuters in the Corpus Christi area for up to four weeks beginning July 23.Starting at 6 a.m. that day, the exit ramp from northbound Interstate 37 toward northbound US 181 and the Martin Luther King Drive frontage road toward the loop ramp for southbound State Highway 286 will be closed through mid-August. The extended closure is necessary to continue restoration work and complete the final alignme…