Minnesta trunk or state highway, what's the difference?

Crosstown Hwy. 62 is a continuous four-lane route through the heart of the south metro. But Drive reader Jeanne Cur wondered why her GPS refers to it in different terms along its 19-mile run from Minnetonka to Inver Grove Heights.

"My GPS alternately calls it 'State Highway 62' and 'Trunk Highway 62,' " she wrote in an e-mail. "What is the difference between a Trunk Highway and a State Highway, and why does Hwy. 62 have both designations in different areas? This can be confusing."

Minnesota Department of Transportation (MnDOT) spokesman Kent Barnard isn't sure why GPS systems use the terms interchangeably. "Both are correct," he said.

A trunk highway system is a network of interstates and state highways that, similar to the trunk of a tree, serves as a main route connecting cities, ports, airports and other important locations within the state, Barnard said.

The system in Minnesota began developing when the Legislature created the State Highway Commission in 1905. Just over a decade later, the Legislature abolished the commission. In its place, lawmakers in 1917 created the Department of Highways and named Charles M. Babcock of Elk River as its first commissioner. The name change and expanded scope of the department's duties "reflected the need for a roadway system able to handle the growing numbers of motor vehicles," according to a history of MnDOT.

There were 920 motor vehicles registered in Minnesota in 1903. By 1920, there were more than 324,000. The Babcock Amendment of 1920 allowed the Department of Highways to create a system of 70 trunk highways. "Under Babcock's leadership, Minnesota developed a highway system to transform the state's dirt roads into travel and paved roadways and highways," Barnard said.

Today Minnesota has about 12,000 miles of trunk highways, making it one of the largest road systems in the nation, said spokesman David Aeikens.

In one of the state's road oddities, the Crosstown is not the only Hwy. 62 in Minnesota, and that's something Drive reader Jim Accurso wondered about.

"I drive for work across the southwestern quadrant of the state and I cross Hwy. 62, which seems to begin in Windom in Cottonwood County and heads west toward Slayton in Murray County," he wrote in an e-mail. "But there's also a Hwy. 62 here in the metro in Dakota and Hennepin counties. What gives?"

The Crosstown was built by Hennepin County in the 1960s and was numbered as County Road 62 because it ran parallel to 62nd Street in south Minneapolis. The road was turned over to MnDOT in what was dubbed the Great Swap of 1988, Barnard said.

MnDOT kept the number 62 even though a Hwy. 62 already existed between Fulda and Windom. Barnard said he believes that the heavily traveled highway in the Twin Cities was far enough away from the one in southwestern Minnesota that it would not confuse drivers.

The same year, MnDOT also assumed responsibility for County Road 18 in the west metro, which became Hwy. 169. In return, Hennepin County took what is now County Road 81/Bottineau Boulevard from Robbinsdale to Maple Grove; County Road 25 in St. Louis Park, which was formerly Trunk Hwy. 7, and County Road 101, formerly Trunk Hwy. 101 in western Hennepin County.

Follow news about traffic and commuting at The Drive on startribune.com. Got traffic or transportation questions, or story ideas? E-mail drive@startribune.com, tweet @stribdrive or call Tim Harlow at 612-673-7768.