SALEM — This is E-Day.

This is the long-awaited and, for some, dreaded day that the east ramp closes between North and Bridge streets. That may not sound like a big deal, but the ramp closing and simultaneous installation of a traffic light nearby has been the subject of fierce public debate.

There are fears that the two events will cause long backups throughout the downtown and force cars to seek shortcuts through the neighboring McIntire Historic District, where residents in Federal Period homes live in relative tranquility.

"We're very concerned about the impact of that light on downtown Salem ... as much as (on) our neighborhood," said Meg Twohey, co-chairwoman of the Federal Street Neighborhood Association. "We think that the backup could be huge."

They may have reason to be worried.

A few weeks ago, when the Massachusetts Highway Department installed a new traffic light a short distance away at North (Route 114) and Mason streets, it did not go well. The backups got so bad that the light was temporarily decommissioned.

That light is working more effectively now, but still causing backups at rush hour, a city official said. The state is expected to fix the problem in the next week or so.

Today's roadway controversy also centers, at least in part, around the tiny east ramp, which is located across from the entrance to the commuter rail station.

Although it carries about 800 cars during rush hours and a few thousand cars a day, it has done a good job of staying out of the news.

Unfortunately for the ramp, it is located next to the site where the state plans to build a $106 million courthouse, and the land is needed for the project.

But closing the ramp and erecting a traffic light have proved as complex as any chess move, triggering countless community strategy sessions and immeasurable angst.

A consultant hired by the city held a series of meetings with neighbors and city officials, all searching for a way to prevent the historic district from becoming a shortcut for motorists trying to avoid the light.

Their solution? For the moment — do nothing and see what happens.

At 6 a.m. today, the city got its first look at the new intersection. The ramp was scheduled to close and the light to start working. While neighbors are bracing for the worst, the city is hoping for the best.

"We expect it to go well," City Engineer David Knowlton said, "but with change there is always a challenge."