Maryland drivers are going to have their first experience with a style of interchange called a diverging diamond. The construction project at the Baltimore Washington Parkway/Arundel Mills Boulevard interchange is scheduled to be completed by late summer.
The project is pegged to the scheduled opening on June 6 of the Maryland Live! Casino, a short distance east on Arundel Mills Boulevard, and is designed to accommodate the increased traffic to and from that area.
This diverging diamond style — a diamond interchange with diverging lanes in the middle — is going to take some getting used to. It’s designed to improve safety and traffic flow by eliminating the roundabouts on either side of the parkway and having the traffic lanes cross over so the traffic movement is simplified — at least from the driver’s point of view. On a map, it looks weird, because the traffic lanes cross over.
While it will be a first for Maryland, this style of interchange has been used elsewhere. You can see a video of the diverging diamond here.
The crossover of the lanes will be controlled by traffic signals.
The Cordish Companies, developers of the casino, will cover the $5 million cost of the traffic improvement project, in coordination with the Maryland State Highway Administration and Anne Arundel County.
Construction is starting now, and drivers should experience the new traffic patterns by early June, though the full project won’t be done until late summer.
The sponsors acknowledge that there’s going to be a learning curve for drivers. Here’s the cheat sheet.
To go northbound on the parkway from the boulevard: Driving west, move into the boulevard’s far right lane and merge directly onto the parkway.
To go south on the parkway from the boulevard: Drive west and stay in the left lanes. Continue through the crossover point — controlled by a light — where drivers will move to the left side of the roadway and merge directly onto the southbound parkway.
Going northbound on the parkway to the boulevard: Stay to the right when the off-ramp divides and merge onto the eastbound lanes of the boulevard.
Going southbound on the parkway to the boulevard: After exiting the parkway, stay left and merge directly into the eastbound traffic lanes. Continue through the crossover where your lanes switch to the right side of the roadway onto the boulevard.
It sounds confusing, but drivers will get used to it after a couple of weeks. Just don’t get upset that for a short distance your traffic lanes appear to be on the wrong side. After that short span, the lanes will straighten out to your benefit.
The more difficult part may be the current phase of construction. Southbound connections between the parkway and Arundel Mills Boulevard will be closed for about a month. The work will go on round the clock to speed the project.
Detours to Route 175 and Route 100 will be posted.
This construction phase is going to increase congestion and slow travel times, the planners acknowledge.