With the new system, a computer will constantly monitor traffic levels and adjust the timing of the lights based on the number of vehicles and the time of day.
The state and the city are wrapping up a $1.5 million joint project in which traffic signals at 56 intersections were replaced or improved.
In some cases, when new signals were installed the timing of the lights was thrown off, causing delays. Small said the old and new systems didn't mesh well.
Potomac Street was mentioned as one of the troublesome spots.
"It just drives me crazy," said Councilman J. Wallace McClure, who has contacted the city engineer's office several times to push for improvement.
McClure said it is "a straight shot" for him to drive up Potomac Street to his job, but it's a path he has been avoiding because of the delays.
"It's certainly refreshing to find out something's happening sooner than you thought," McClure said. "I'm happy that we have a resolution."
State crews worked Wednesday and Thursday to connect each of the downtown intersections to the network.
Small said there may be some bugs when the system starts up on Friday. "Sometimes signals just don't talk to each other, get out of step," he said.
Technicians will be sent to fix any problems, and crews will drive along all of the streets to study the timing.
Drivers who notice unusual signal patterns may call the city engineer's office at 301-739-8577, extension 125, and name the intersection and the exact time of day.
In six months, the state will re-evaluate the system, Small said.
Assistant City Engineer Rodney Tissue said the state completely replaced 28 signals on U.S. 40. The city also worked on 28 signals, replacing 15 and installing new computer boxes on 13, he said.
The city's share of the project was budgeted at $670,000, which included moving wires underground, replacing signals and controllers, and repairing sidewalks, Tissue said.
He said the project appears to be coming in under budget.
It will be easier for the city to adjust the lights in case of a special event or a fire that would alter the traffic flow, Tissue said.
Nancy Jones, a traffic engineer with the state, said the new synchronization will allow drivers, in theory, to travel through a series of green lights on U.S. 40 if the road are clear.
The city engineer's office said traffic flow is expected to improve the most on Potomac Street, U.S. 40, Burhans Boulevard, Locust Street, Jonathan Street, Mulberry Avenue and Cannon Avenue.
There will be some improvement on Baltimore Street, Antietam Street, Church Street/East Avenue and North Avenue, according to the city.
That comes as good news to Tony Surrano of Oak Hill Avenue, an environmental safety specialist for the Washington County Board of Education. He has been cutting over to Mulberry Street instead of using Potomac Street for the drive to work.
Surrano said he is pleased by the imminent improvement, but still plans to avoid the traffic signal at Oak Hill and Northern Avenue, just a block from his home. "You can sit there forever," he said.