CEDAR RAPIDS — The Iowa Department of Transportation may have to alter some snow removal routes after a wave of crashes totaled two snowplows and damaged several more during Iowa’s first big storm of the season earlier this month.In one case, on Interstate 35 north of Williams, in Hamilton County, a semi roared up at 70 miles per hour and rear-ended a snowplow, which typically doesn’t exceed 35 miles per hour while on duty, said John Hart, an engineer with the Iowa DOT.