Thursday, October 08, 2009

Arlandria Intersection Improvement Meeting Summary

The City followed up on a March meeting about intersection improvements at the intersections of W Reed Ave and W Glebe Rd with Mt. Vernon Ave on Wednesday, Sep 23. Neighbors and a business owner or two were on hand for a presentation to review the preliminary design work of Kimley-Horn and Associates, Inc. Four alternatives were presented.

Existing Intersection Issues
First, here's a little background from the 2008 Pedestrian and Bike Mobility Plan to get an idea of why this intersection is at issue. There are traffic and aesthetic issues, as well, but let me outline some of the safety concerns.

The first graphic, below, shows the intersections in question had medium crash density compared to similar sites, city-wide. The only high crash density in the city was just North between Russell Rd and Four Mile Run on Mt. Vernon Ave. I suppose work to resolve those issues will fall to a future effort.

This second chart identifies these intersections as providing fairly poor quality crossing conditions. This supports the need to make improvements at the two sites.
Finally, this third chart demonstrates the high volume of potential pedestrian activity. The relatively poor crossing conditions coupled with a high potential pedestrian activity further support the need to increase the quality of these intersections for pedestrians to avoid future pedestrian-related accidents at this site. Additionally, any effort made to give Arlandria more of a sense of place is a step in the right direction.

The Mt. Vernon/W Glebe Alternatives
Now that we have a little background, let's get to the good stuff. While four alternatives were presented for the W Glebe/Mt. Vernon intersection, only one option was presented in depth. Here is the full presentation.

The first three alternatives presented would require significant redevelopment to become possible, as they required the city to acquire additional right of way to carry out. The three throw-aways were 1) a roundabout with an offset approach, 2) a realignment to square-up the intersection, and 3) offsetting Mt. Vernon Ave (see following 3 images from the presentation for clarity). The roundabout option seemed overly complex compared to the one I mocked up in an earlier blog entry, though admittedly, my mocked up design was only loosely based on what roundabout standards I could find in various documents from VDOT and Maryland's DOT. Even my version requires the city to acquire right of way from 2 intersection-adjacent property owners.

The fourth option is one that could be done within the existing right-of-way. Right-turn slip-lanes are created for both right turns off of Mt. Vernon Ave. Generally that change is considered a setback for pedestrians, but they plan to add additional traffic calming features designed to make the slip-lane feel like a pedestrian oriented space. Finally, the design includes shortening crossing distances by adding a pedestrian island at the northwest and southeast corners that narrow the intersection. The pedestrian island might include certain "gateway" features to make the intersection feel more like an entrance to Arlandria, but what that means remains to be seen.

Primary citizen concerns with this intersection alignment were that it is still not pedestrian-oriented enough. Some were concerned about slip-lanes, though it seemed the extra pedestrian features of the slip-lanes allayed their fears.

One suggestion was to make the right turn lane on eastbound W Glebe a straight and right-turn lane and to make the other lane a signaled left-turn lane. Staff explained that approximately the same portion of traffic goes right as goes both straight and left combined. Citizens were surprisingly less concerned with the traffic flow issues in favor of making the intersection more pedestrian oriented. As a worst case scenario, if the City makes the citizen recommended change and it does not work well, the City could cheaply put the lane alignment and signals back as they are shown in the diagram above.

Reed and Mt Vernon Intersection Improvements
Only a single option was presented for Reed/Mt. Vernon. It added bulb-outs to narrow crossing distance and an additional cross-walk, primaritly to get to and from the bus stops. Citizens thought adding a cross-walk both North and South of the intersection would make more sense. At the very least, the cross-walk should be on the north side instead of the south side, where the road will become narrowest.

Another big question was about a future plan to extend Reed into the Safeway/Datatel site and connect it to W Glebe Rd, as was suggested by the Arlandria Long Term Action Plan. People asked if all this work would be necessary if that plan goes through. City Staff said the current effort makes that effort more feasible in the future. It consolidates some driveways and makes the entrance to Wachovia better aligned with Reed. If the road were ever extended, it would likely pass through this same curb-cut.

Overall Concerns
Many were concerned about cost. The impression we've been given by the City is that the $500K in Capital Improvement Project (CIP) funds set aside for "Revitalization of Arlandria" have to stretch over several projects. It looks like these intersection changes will take up somewhere in the $200K to $300K range (perhaps a little bit less) of that $500K. Sandra Marks said the project has not been approved yet and the soon to be formed Arlandria Implementation Advisory Group could have a say in prioritization of the project (more on formation of that group very soon). A delay for prioritization could impact the project start date. Attendees were mixed between getting something done ASAP and making sure this is where we want to spend much of the available CIP funding.

Other concerns were that if the engineering phase of the project were started today, actual construction would not begin until summer 2010. If we agree to this project, why does it have to take nearly a year to get started?

In all, it was a productive meeting, even if we felt we were not really given alternatives to work with. The city is, at least, trying to move forward with one major project in the area. The question still remains why this project was chosen over many others, but perhaps it was just a target of opportunity since changes can be made to the existing right-of-way.


Unknown said...

I think this was an thorough outline of the meeting. I do agree that is not exactly the best use of the funds. There is a lot in the Arlandria plan that could benefit the area. I don't see the immediate need for these changes.

Unknown said...

"One suggestion was to make the right turn lane on eastbound W. Glebe a straight and right-turn lane and to make the other lane a signaled left-turn lane. Staff explained that approximately the same portion of traffic goes right as goes both straight and left combined."

It sounds like the point was missed here: Traffic volume is irrelevant since with the current configuration, it takes only one car waiting to turn left to block all the traffic hoping to proceed straight across Mt. Vernon. This creates a dynamic were cars dart into the right lane to cross Mt. Vernon – especially dangerous given the other problems at this intersection.

By switching to a configuration where right-turn traffic and straight traffic share the same lane, cars in the shared lane will be able to flow freely while left-turners wait for an opening to make their turn. This is an easy fix and doesn't require a left-turn arrow – just new signage.

Unknown said...

I don't see why the roundabout would need to have lanes realigned. The sharp turns are rarely taken if you look at the larger context of road connections in the area. That would make that solution much easier to achieve.

Unknown said...

I don't think this traffic calming would be a good use of 40-60% of the allocated funds. I admit I'm biased, but did anyone else note that using these funds benefits the drivers turning right onto Mt. Vernon from eastbound W. Glebe? That means this solution serves not Arlandria (which I'd like to brand "North End") but rather serves the wealthier Del Ray and Warwick Village neighborhoods.
At a time when the people of Hume Springs can't even get bus shelters on Mt. Vernon north of Glebe, I can't see why we're spending more money to serve our southern neighbors. This neighborhood could use so much more than a bus crossing for the modest bus route that takes us north or south to public transportation... especially since public metro transit will still be based outside walking distance to serve the residents of Potomac Greens instead of Lynhaven and Hume Springs and Arlandria.
I apologize that I was not able to make the meeting, and I appreciate the considerable thought... I'd just like to see a more beneficial use to the funds allocated.