The District Department of Transportation now hopes to partially open the local span on the 11th Street Bridge this Thursday morning. The opening, one of several important developments in the District’s biggest road project, will affect traffic patterns on both sides of the Anacostia River.

Some of the traffic patterns will be temporary, but one permanent change will be the closing of the 13th Street ramp onto the bridge from the Anacostia side. While the ramp closing will disrupt traffic, the bridge opening also will provide new access to the Navy Yard’s O Street entrance.

The new span, the third and final one to open as part of the project, will have two-way traffic and a pedestrian path. It’s designed to provide local access between Anacostia and the Navy Yard area. The other two spans offer connections for through traffic.

None of it is quite done yet, even with the opening of the new span. Peter McDonough, construction manager on the project, took me on a tour last week in which he showed me how the pieces fit together.

I’ve described the project as somewhat similar to the construction of the Wilson Bridge, during which a new span was built, traffic diverted from an old span, then the old span demolished. And that is the basic idea: The impact on traffic was largely limited until this final phase of construction.

But that description doesn’t capture the tight work space, and connecting routes on either side of the river that basically come in at right angles. Drivers traveling through the work zone see weird combinations of new and old. Nice, smooth stretches of concrete link to rough old asphalt. Open ramps curve past the steel frames of unopened ramps that end in mid-air.

Those pieces will gradually be connected during late-spring, summer and fall. The project will be substantially done by the end of the year. One of the big developments scheduled for an opening by July 4 is the new ramp linking southbound 295 to the inbound 11th Street Bridge. Then a few months later, commuters will have a new link from the outbound bridge to northbound 295.

Several generations of commuters have awaited those connections.

About the same time, a new ramp from 11th Street SE to the westbound Southeast-Southwest also should open. That will reestablish the connection to the freeway for local traffic and end one of several detours drivers will have to learn about later this week.

In fact, this week’s temporary changes are likely to cause some traffic delays during morning rush hours. Let’s review them.

When the local span opens, it will be configured to provide two lanes for inbound traffic, heading in the direction of downtown D.C., and one lane for outbound traffic, heading toward Anacostia.

A temporary walkway six feet wide will provide access for pedestrians and cyclists. When the span is complete this fall, it will have four traffic lanes and a path for pedestrians and bikers.

At the same time the span opens this week, the 13th Street ramp will shut. The ramp has provided access from Good Hope Road to the inbound bridge.

When the ramp closes, inbound traffic from Anacostia will be directed to the intersection of Martin Luther King, Jr. Avenue and Good Hope Road SE to reach the new local span.

This is likely to generate extra traffic congestion around Martin Luther King Jr. Avenue and Good Hope Road SE, where traffic will now go onto the local bridge span to cross the river. As drivers cross the river, they will arrive at the O Street SE intersection, where the Navy Yard entrance is to the left. If they turn right on O Street, then left onto 12th Street SE, they can reach M Street SE.

These drivers using the new local bridge won’t have a direct connection to the westbound Southeast-Southwest Freeway. To reach the freeway from M Street SE, they can make a right on 11th Street and go north to I (Eye) Street, where they turn left. I Street leads into Virginia Avenue SE and eventually to the Third Street SE ramp onto the westbound freeway.

Or they could continue on M Street and make a right on Third Street to reach the freeway ramp. Another option from the Anacostia will be to drive south on MLK Jr. Avenue, make a right on Howard Road SE and get onto I-295, which leads to the inbound freeway bridge.

But if enough drivers do that, it could lead to some additional traffic congestion south of the bridge.