Sunday, January 12, 2014

BRT & Four Corners: Losing travel lanes does not spell disaster

I figured I would make my first BRT post about the most common complaint towards BRT: the loss of general purpose travel lanes for the creation of bus lanes.  The Countywide Bus Rapid Transit Study recommends at least one dedicated BRT lane on both University Blvd and Colesville Road in Four Corners, with a short stretch of BRT in mixed traffic on University Blvd in the immediate vicinity of the intersection.  (see map).  The creation of dedicated lanes for BRT in Four Corners does not necessarily mean travel lanes will be lost, but converting existing travel lanes to BRT lanes is actually the best way to implement the system (as counter-intuitive as that seems).  For this post, I will talk about the most cost effective and least intrusive (no road widening or loss of medians) way of creating bus only lanes: converting existing left lanes to BRT lanes.  This is the method that was favored by County Planners in their recommendations a year ago.



View Larger Map Red lines denote at least one dedicated lane. Blue lines denote BRT in mixed traffic. Map courtesy of Dan Reed.


Dedicated right-of-way is crucial to the success of Bus Rapid Transit.  Without dedicated lanes, BRT becomes just another slow moving bus.  This watered down version of BRT is known as "BRT Creep".  In Four Corners, the cheapest and simplest way of implementing BRT in dedicated lanes would be to convert the existing left lanes of Colesville Road and University Blvd to BRT only lanes.  This would leave 2 general purpose travel lanes each way for other vehicles on each road and a number of turn lanes.

This is the lane layout on most parts of University Boulevard and Colesville Road.  

This is what dedicated Bus Rapid Transit lanes could look like in the left lanes, with a median BRT station.  No road widening would be necessary, meaning no properties would be affected.
Many residents of Four Corners are concerned (and rightly so) that the removal of general purpose travel lanes will cause more traffic backups.  Many residents are also alarmed because there is no example of BRT in our area.  There is no local precedent for us to look at to see what BRT could mean for us.  Many people I've spoken with seem to think the loss of  travel lanes on Colesville Road and University Blvd will have catastrophic impacts on traffic.  As I was walking along University Blvd over the Beltway a couple days ago, I realized the precedent for going from 3 lanes to 2 has already been set here in Four Corners.

The right lane of University Blvd westbound over the Beltway has been closed for more than 4 months (more on whats taking so long in another post)  in preparation for bridge deck replacement.  This closure has had little disruption to traffic, as most drivers have now gotten used to the new traffic pattern and act accordingly.
Four months ago, the right lane of University Blvd westbound became a "right turn only" lane just past the intersection with Franklin Avenue, reserved for drivers turning onto the Beltway ramp from 193.  After that, 100 yards or so of the right lane remains closed until the next ramp, where it once again becomes a turn lane exclusively for cars going to the Beltway.  The lane is again closed for a short distance until it reopens as a normal lane at the next Beltway off-ramp.  This lane had previously been a regular travel lane that was shared by through traffic and vehicles turning onto the Beltway ramps.  So what does this short lane closure on University Blvd have to do with BRT?  It is proof that you can close a travel lane on a major artery, at an interchange with the Beltway, and not have consistent traffic delays.

2012 aerial photo of University Blvd and the Beltway.  I drew in the right lane closure that currently exists.
Traffic on University Blvd tends to be heavier westbound in the morning and eastbound in the afternoon.  While the lane closure does not have an impact on traffic most of the time (23 hours a day), it does cause some delays in the morning for drivers travelling westbound on University Boulevard.  Whenever a lane is closed, a traffic backup is caused by people merging from the soon-to-be closed lane into the next lane over (in this case; from the right lane to the center lane).  Traffic in the center lane is forced to brake for the slower moving vehicles merging in from the right lane.  This causes a ripple effect that can back up University Blvd to Eastern Middle School.

How can you use this closed lane as an argument for BRT if it causes delays for drivers during the morning rush hour?

Because; it is not the absence of the lane that causes delays, rather, it is the merging and braking of drivers trying to squeeze through the existing lanes that causes backups.  A stretch of River Road (MD Route 190) in Potomac that is only 2 lanes wide sees an average of 20,900 vehicles a day.  The stretch of University Blvd by the Beltway averages 43,000 vehicles a day.  If a 2 lane country road can accommodate 20,900 vehicles a day without delays, a 4 lane divided highway such as University Blvd (which it would become if the left lanes became BRT only) can accommodate 43,000 vehicles a day without delays.  Don't believe me? You don't have to, because there's already an example of a 4 lane road accommodating over 43,000 vehicles a day without problems: the same River Road, inside the Beltway.  According to SHA traffic volume data, the 4 lane stretch of River Road between Wilson Lane and the Capital Beltway carries 46,000 vehicles a day, 3,000 more than University Boulevard's heaviest traveled point.  This section of River Road and University Blvd have similar speed limits and a similar number of traffic lights.  I know for a fact that traffic on River Road isn't bad, because if it was, all of the wealthy and politically connected people that live over there would demand that it be widened to 6 lanes (There's plenty of room to do so, the road has full shoulders which could easily be converted to travel lanes if needed).  So, if only 4 travel lanes for 45,000+ vehicles a day is good enough for Potomac, it's good enough for us.

What does this have to do with losing a lane for BRT?

University Blvd widens from 2 lanes to 3 in Kensington going eastbound, and it widens from 2 lanes to 3 in Langley Park going westbound.  What if the amount of travel lanes each direction were to remain at 2 for its entire length, with the 3rd lane being used for BRT?  There would be no traffic jams from people merging out of a closed lane, because the lane (as available for general traffic) would never have started.  While there is not example of BRT in our area, there is precedent for narrowing a road for its entire length with no traffic delays: Queens Chapel Road in Hyattsville.  The left lanes of Queens Chapel Road were closed permanently 10 years ago, reducing the number of travel lanes from 6 to 4 throughout its entire length.  Since both of the roads that feed Queens Chapel are 4 travel lanes wide (Adelphi Road to the North and Michigan Avenue NE to the South), there are no delays caused by the narrowing of the road.  The same thing could happen on University Blvd, as it is also fed by 4 lane roads at either end.

Hogwash! Losing a lane would mean losing 1/3 of road capacity each way. No way 1/3 of road users will switch to BRT!

Not exactly.  The 1/3 capacity argument seems like a logical one, until you stand next to University Blvd or Colesville Road for a while.  If traffic flowed at a consistent speed and frequency in all three lines, this logic would hold true, but this is not the case.  Traffic on roads like University and Colesville does not flow at a fairly consistent rate like traffic does on a limited access highway (such as the Beltway).  This is because of traffic lights, which cause vehicles to come in waves.  This traffic pattern causes long gaps in between groups of cars, which leave periods of time where the road sits completely empty.  Even at rush hour, you will see this pattern:  gaps in traffic, then a wave of cars, then another gap.  The primary cause of congestion around Four Corners is not simply the sheer volume of traffic, but the inefficiencies of traffic lights (more on that in another post).  If BRT took away a lane each way from cars, it would not cause major delays, it would just lengthen each wave.  There would still be plenty of unused road space.

An example of the massive gaps in traffic that occur on University Blvd and Colesville Road.  This picture shows a 550 yard stretch of Route 193 in the vicinity of Caddington Ave, just south of Northwood High School.  Route 193 is comprised of 6 total through lanes at this point, each lane being 11 feet wide.  550 yards (1,650 feet) x 6 lanes = 9,900 feet of total lane length x 11 = 108,900 square feet of road space.  There are only 3 cars on the road in the picture.  That means over 99.8% of this road space was unused at the time of this picture.  This aerial image was taken on Monday, January 31st 2008 around 11 AM. 
That picture is of an open stretch of road at an off-peak time.  The loss of a 3rd lane at traffic lights at rush hour would cause major back ups.  

While ques at traffic lights may be extended by the loss of a 3rd lane to sit and wait in, better light timing and the appeal of rapid transit could mitigate this effect.  Those who can take the bus to their destination will be more inclined to do so, meaning those who can't take BRT will benefit from less cars on the road in front of them, both at traffic light ques and on open stretches of road.  And remember, River Road only has 2 travel lanes each way, and it accommodates more traffic than University Blvd, which has 3 travel lanes each way (46,000 vehicles a day on River vs 43,000 vehicles a day on University). The 3rd lane is not as essential as we think it is.

Over 20,000 people a day ride buses to and through Four Corners, yet these people sit in the same traffic as vehicles with single occupants.  An average of 11,265 people a day pass through Four Corners on the C2 and C4 MetroBus routes, both of which travel on University Blvd.  An average of 8,043 people travel through Four Corners each weekday on the Z 2, 6, 8, 9, 11, 13, and 29 MetroBuses that run along Colesville Road.  An additional unknown number of transit users take the RideOn 21, 22, 19, and 9 buses through the intersection each day.  Converting one lane each direction to transit is the most efficient thing to do if we want to move as many people as possible, instead of as many cars as possible.

In future posts I will talk about what BRT would be like on Colesville Road.  I will also address many other BRT concerns, such as traffic patterns, station locations, interaction with Beltway merge lanes, etc.   Remember that the logistics and forms of implementation are not set in stone, as various options are being considered.  Now that the plan has been approved by the County Council, more detailed studies are being done on each corridor.  If you choose to comment, read the whole post, and please be civil.

10 comments:

  1. I wish I shared your conviction that there will be no road widening. If there is even the slightest change in road configuration, such as repaving of the median strip to accommodate BRT bus stations, that triggers State Highway regs requiring new bike lanes, utility rights of way, and the like, which all require widening. Larry Cole of the planning board concedes as much. Road widening=loss of front yards and driveways on Colesville Rd, but the county will be able to blame the state.

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  2. There is only one planned BRT station on Colesville Road in Four Corners. If it is in the median, it will be on the stretch of median between the two directions of University Blvd, between 7/11 and the church. If these state regulations you're alluding to only require road widening where the the road is altered, then that is the only stretch where they will add bike lanes (which are only 5 feet wide). Since that small stretch of Colesville Road is in the middle of the commercial district, there will be no yards or driveways taken because no one lives there. However, I'm not sure those regulations are mandatory, the intersection of MD 410 and Adelphi Road in University Park was reconfigured just 3 years ago, and the road wasn't widened and no bike lanes were added, even though there were significant changes to the turn lanes at that intersection: http://goo.gl/maps/7kKak If they got some kind of exemption because of the close proximity of homes to the road, we could too.

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  3. County Council staff talked about that exemption in a memo to Valerie Ervin. It applies only where there are no driveways or very few. That's not the case on Colesville Road or University east of 29.

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    1. Also, have you seen the new signs on Colesville Road that say bicyclists can ride in the same lanes as cars? I can't imagine anyone taking a chance like that. I'm wondering whose bright idea that was?

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    2. This regulation only applies where the road is altered right? Like when they built the new ICC interchanges, they put bike lanes in along the part they altered to build the interchange but after that the road goes back to normal. (I have NH Ave ad Layhill Rd in mind) So for BRT on Colesville the only part of the road that would need bike lanes (if no exemption is possible) would just be the part between 7/11 and Marvin Memorial where the station will be. If that is true, then most of Colesville Road from NW Branch to Franklin Ave would not require widening as there are no other planned stations along that stretch except the Four Corners one. As for those signs, I appreciate the sentiment, but any cyclist who tries 'taking the lane' on Colesville or University is going to be in a bad situation. There's one on Colesville Road at Crestmoor (probably the one you're talking about) that seems especially ridiculous because cars go 50+ MPH on that downhill to Burnt Mills. Those signs seem to be on all the SHA arterial roads now, I've seen them over in PG county as well.

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  4. Comparing River Road traffic to 29 and University is a bit of a stretch. As you point out the traffic will be twice the volume of what is on River Rd. Also try driving on Queens Chapel Rd during rush hour--it is a nightmare. I ask you what residents of 4 Corners have asked for this?

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