The Marshalltown Police Department is cautioning about a construction project that is underway along South 18th Avenue on the far east side of Marshalltown. A road construction project started a few days back with stretches of the very busy normally four lane roadway down to one lane either way. A car versus semi accident sent a person to the hospital via helicopter. This is also an area where there is a lot of traffic in and out in the area of the construction of the Marshalltown Generating Station. The construction project is expected to last until the end of the September.