"It will make Frederick safer," he said, because it will divert traffic away from downtown.
It also enhances the area's good transportation network, which has helped to lure new businesses here, especially distribution centers, he said.
The ramps also will mean quicker response times for emergency crews, said Frederick Mayor James Grimes.
Construction began in July 1995 on the project, which is the first step toward upgrading other interchanges along I-70 through Frederick.
The State Highway Administration has proposed a total of $150 million worth of improvements in the area.
The next phase would be construction of missing links between interstates 70 and 270 and reconstruction of New Design Road over I-70.
The importance of highway construction is evident in the gridlock of I-270 in Montgomery County, Md., Glendening said.
In the next 20 years, traffic in that corridor is expected to grow by 60 percent, he said.
Glendening warned that the government needs to find alternatives for people commuting to Washington, D.C.
One thing that will help are two planned MARC train stops in Frederick, expected take 1,600 commuters a day off the highways.
Construction of the 13-mile track extension to Frederick is scheduled to begin in 1998. Two-thirds of the project has been funded by the federal and state governments, Glendening said.