Tuesday, May 13, 2014

About the Lane Closure

The right lane of Route 29 closed between Crestmoor Drive and Northwest Branch because of damage from April 30th's flood.  Photo by the author.  

Traffic in Four Corners has been particularly bad these last two weeks due to the right lane closure on Route 29 North at Burnt Mills.  At rush hour, 29 has backed up so badly that it has gridlocked the intersection at Four Corners, affecting traffic on University Boulevard.  The State Highway Administration hopes to have repairs completed within a week.  The job was supposed to be done sooner, but the original contractor failed to show up.  This long term lane closure provide an interesting case study, especially with the proposed bus rapid transit line on Route 29 from Silver Spring to Burtonsville.

This stretch of Route 29 carries about 60,000 vehicles per day total.  That's about 30,000 vehicles travelling each direction every day in 3 lanes, for about 10,000 vehicles per-lane per-day.  10,000 per day divided by 24 (hours in a day) is roughly 416 vehicles per hour.  Of course, traffic is much heavier during certain hours of the day than it is during others.  The number of vehicles per-hour at rush hour is exorbitantly higher than it is in the early morning hours (I wish I had hourly data but I don't, however, it's safe to assume that the vehicles per hour count is way higher at rush hour than it is in the early morning hours).

The biggest concern I've heard about bus rapid transit is the potential re-purposing of general purpose travel lanes to bus-only lanes.  Keep in mind that at this preliminary stage in the planning of the BRT network, nothing is set in stone.  The county planning department does not even have favored methods of implementation at this time for specific locations along routes, just general ideas.  This means that the planning department has not yet even thought about what style of implementation would be best for a specific place like Route 29 at Crestmoor Drive, because it is still so early in the planning stages.  The county will set up citizens advisory committees which will help the planning department determine what methods of implementation are best for which areas.

So what about the lanes?  I could go into a discussion of numbers and analysis to show how loosing the right lanes would not be as bad as we think, but I won't because I don't think that re-purposing the right lanes on Route 29 is the best way to implement BRT through Four Corners.  I think there should be a one lane busway in the median, with off-peak buses using the three remaining general travel lanes in each direction.  A bus going southbound in the morning would use the dedicated lane, while a bus going northbound in the morning would use the regular lanes which have less traffic because they are in the opposite direction the prevailing flow.  Right lanes are slow, since they have things like turning cars, delivery trucks, and other non-BRT buses.  Putting BRT in the median separates it from other modes of traffic, providing an even faster ride.

Wheat a median busway would look like within the existing 84' curb-to-curb width of Route 29 in most parts of Four Corners (the part through the intersection is much wider than 84').  The use of the lane would depend on time of day.  In the morning, southbound buses would use it.  In the evening, northbound buses would travel in it.   
I will elaborate more on this topic in future posts.  I have created an overlay in Google Earth (a GIS software that allows users to add points, lines, and polygons to aerial images) showing what a median busway could look like through all of Four Corners.  I figured out how to feasibly preserve left turn lanes at places like Timberwood, Southwood, and Crestmoor with a median BRT lane (which in turn preserves 6 travel lanes) without negatively impacting private property or businesses.  I'm going to make a post about each intersection describing what a median BRT lane could look like going through it.  The first post will be about the intersection of Route 29 & Timberwood Drive, since preserving a left turn lane there is important for accessing the Woodmoor Shopping Center.  BRT is not a one size fits all deal; it is a flexible form of transit (much more so than rail) that can be adapted to best serve the communities it passes through.

I had to make a post about this lane closure because I've heard people use it as a reason why BRT should not be built through Four Corners.  This is a moot point since BRT can be implemented through Four Corners in a way that keeps 3 travel lanes in each direction at all places without complete road widening or loss of private property, and we can even keep at least one left turn lane into each of the neighborhoods along the route.  It's all about implementation.        


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