Although drivers are currently enduring months of traffic and detours, at the completion of the expansion of the U.S. Highway 75 in McKinney, traffic flow will be smooth. The exit ramps and frontage road lanes will open soon in the coming weeks, although construction works will still continue in other locations along the highway. With this, officials said that it will probably take a year before one of Collin County’s main highways will be completely clear of construction and its equipment. The construction project is headed by the Texas Department of Transportation in order to add lanes to widen frontage roads and McKinney’s entrance and exit ramps near Edorado Parkway. The additional highway capacity is due to the expected growth of the County’s population to over a million within the next decade, which might cause congestion on the existing road systems in the area. The construction will be patterned to TxDOT’s project at Parker Road in Plano last December 2010. Th…