Four Corners Station

The Better BRT plan recommends a dual median busway and median station for Four Corners.

Background

After crossing the Beltway, Colesville Road widens to 104’ with eight total lanes, six travel lanes and two temporary/turn lanes. Prior to 1998, this segment of Colesville Road was only six lanes, when traffic volumes just south of University Boulevard were about 56,000 vehicles per day. Currently, MDSHA data shows that same stretch carrying 64,000 vehicles per day as of 2016, representing a modest increase. As shown below, there are several examples of six-lane roads in Montgomery County that carry similar or greater traffic volumes. The eight lane section of the road begins to narrow just north of the westbound lanes of University Boulevard, narrowing back to 84’ past Timberwood Avenue at Woodmoor Circle.

Traffic counts on similar roads that either have, or recently had, six travel lanes. Data obtained from Maryland State Highway Administration.

By reconfiguring the lanes in the vicinity of the Four Corners intersection, a two-lane dedicated busway can fit in the median, along with stations. This can be achieved by eliminating the left travel lanes and narrowing the remaining lanes to 11’ right lanes and the other four being 10’, for a total of six lanes (essentially returning the general travel lanes to their pre-1998 configuration). This makes for 31’ of space for each carriageway, with 42’ left in the median for a two lane busway and stations.

The removal of the left-most lanes may aggravate congestion during rush hour, but the effects could be mitigated, as noted below. A detailed engineering review would be necessary to determine the degree of the impact to drivers, and if they are outweighed by the travel time savings experienced by BRT customers. If the average travel time for all users of Route 29 can be reduced using this configuration, then it is a more efficient use of roadway and limited space. Because much of the traffic on Route 29 is made up of long-distance commuters, it is feasible that many people that currently drive may switch to riding the Better BRT system, if the latter proves to be a faster and more reliable option.

Designing for maximum reliability

The two lane full-time busway is critical to ensuring that the BRT buses can serve the same platform at all times. At each end of the two lane busway, where the busway transitions back to a single lane, provisions can be made for either merging into the general travel lanes or a bidirectional busway, so that the station may be serviced regardless of time of day. There is no road widening in the vicinity of Four Corners needed to achieve this configuration, it can all be done within existing curbs.

As seen in the image below, the northbound and southbound BRT stations are configured for right side door buses, and they are staggered across the intersection from each other to accommodate the spatial constraints of the intersection. The right turn lane onto eastbound University Boulevard from Colesville Road remains in place. The stations would be accessible by the existing crosswalks and would feature ADA-compliant ramps for wheelchairs. Median BRT stations are safe and are used in various systems across the United States.

Better BRT Four Corners Stations — The intersection of Colesville Road and the eastbound lanes of University Boulevard. The red area is the two lane busway. North is at the bottom of the image. The grass on the top-left is the lawn of Blair High School.

Right-side boarding could eliminate delays to drivers caused by stopped buses

Rather than using a single shared left-side center platform, there would be separate right-side stations for the northbound and southbound buses. This would allow any type of bus to service the station, since most conventional buses do not have left-side doors. Design provisions could also be made that enable local buses like the Metrobus Z8 or RideOn 22 to temporarily enter the two-lane busway between Lanark Way and Timberwood Avenue, service the same platform as the BRT vehicles, and merge back into regular traffic without disrupting BRT operations. Such an arrangement would allow for a seamless one-platform transfer from local services to BRT services, and perhaps most beneficial, it would remove local buses from the right travel lanes of Route 29, removing a bottleneck for motorists. Presently, buses stopping in the right travel lanes of Route 29 delay drivers and can cause unsafe last-minute lane changes. Allowing local buses to service a median platform with right side doors eliminates this scenario and makes the situation easier from transit riders, resulting in a win-win for motorists and riders.

Local bus merge into dedicated lanes — The median break shown here (between Timberwood Avenue and University Boulevard) would allow local buses to enter the dedicated lanes and use the same bus station as BRT vehicles, thereby facilitating transfers.

Changes to turning might be required

Due to the proposed reduction of travel lanes through the intersection, there would less queuing room for vehicles turning off of University Boulevard and onto Colesville Road (where they wait in the space between the two directions of University Boulevard). To mitigate this, the current left turns from University Boulevard to Colesville Road could be reconfigured as “Michigan Lefts”, where the traffic goes straight across Route 29 and uses the existing jughandles to make a left turn. A detailed engineering evaluation would be able to determine if this reconfiguration would be necessary.

Potential Michigan Left travel pattern at University Boulevard.

Adding a second merge lane could also reduce congestion

In another effort to mitigate the lane reduction in Four Corners from eight to six, the ramp from Route 29 south to I-495 west could be expanded from the present one lane configuration to two lanes, with an alternate merge on the ramp itself.

A two lane merge ramp onto the Beltway would allow southbound motorists on Route 29 to use two lanes to access the highway rather than one. Currently, most motorists headed for the Beltway queue up in the right lane of Route 29 as far north as Southwood Avenue, while the left lanes of Route 29 southbound are more lightly used. Allowing the center lane of Route 29 southbound to also provide Beltway access would allow drivers to queue up in both lanes, better distributing the amount of volume in each lane. The center lane could be a “right and straight” turn lane, similar to the one on southbound Georgia Avenue at 16th Street in Montgomery Hills.

Although the figure below shows two southbound travel lanes on Route 29 after the split, there is adequate width in the right of way and the bridge to provide three southbound travel lanes by modifying the southbound carriageway and slightly widening the road into the state-owned land that comprises the interchange.