If the weather has behaved, drivers should see a new ramp from northbound Interstate 95 to Interstate 695 in White Marsh today. The Maryland Transportation Authority planned to close lanes along I-95 and I-695 last night through this morning to open the ramp.
Signs notified the 19,000 motorists who use that interchange daily about the new ramp, which exits I-95 from the right lane and enters I-695 from the right.
The old ramp, constructed 45 years ago, had drivers exit I-95 and enter I-695 from the left.
Back then, the left-lane exit was designed to minimize the footprint of the interchange, said Geoff Kolberg, chief engineer for MdTA.
"We've learned over time it's considerably safer to have ramps on the right side," he said, because it is traditionally the slower lane. "This is better design by today's traffic volumes."
Weather forecasts called for rain all day yesterday, but the ramp was still to open if the roads were dry enough. Otherwise, MdTA officials will postpone the opening until Nov. 23.
From 10 p.m. yesterday until 5 a.m. today, drivers were set to be directed to northbound I-95, to westbound White Marsh Boulevard to southbound I-95, where they could access either eastbound or westbound I-695.
From 5 a.m. until 7 a.m. drivers were scheduled to be directed to southbound I-95 to eastbound I-695 to eastbound Pulaski Highway to westbound I-695.
Kolberg estimated that it would take up to two days for drivers to become accustomed to the new traffic pattern.
During this time, officials recommend that drivers pay attention to the new signs, which direct them to the right-hand exit. The decision point is now about one mile south of the existing location. Drivers should also slow down and obey posted speed limits and maintain a safe distance from the motorists in front of them.
However, MdTA officials did not expect the new route to create traffic backups, because the introduction of other new traffic patterns in this project has gone smoothly.
"We've actually gotten calls saying, 'This is actually a much easier movement,' " Kolberg said.
This portion of the $1.4 billion I-95 express toll lanes project cost $208 million, officials said.
The next component, a ramp from I-95 south onto I-695 east, is slated to open in the spring. The entire project is scheduled to be completed in 2012.
The ramp is part of the first phase of the interchange project; the next phase will be the new express toll lanes.
The new ramp, less than a half-mile long and 110 feet above the ground, is wide enough to accommodate two lanes of traffic, but it is currently painted for just one, Kolberg said.
It was constructed based on estimates of traffic volumes in 2025, project manager Dave LaBella said. It is also designed for drivers to travel the ramp at highway speeds.
After the existing ramp from northbound I-95 to westbound I-695 is closed, construction on the new ramp from eastbound I-695 to northbound I-95 - directly over the location of the old ramp - can begin.