Good News on Infrastructure thread

[bobco85]

@Steve O 162691 wrote:

For the record, the Arlington Bicycle Advisory Committee also recommended elimination of the slip lane, but their recommendation was not heeded by traffic engineering.

Wait, let me play that back in my head: the traffic engineers concluded that keeping the slip lane was the safer option.
The traffic engineers concluded that keeping the slip lane was the safer option.
The traffic engineers concluded that keeping the slip lane was the safer option.
The traffic engineers…

(ILLOGICAL. ILLOGICAL. ILLOGICAL ARGUMENT OVERLOADING BRAIN. SHUTTING DOWN NOW)

[chris_s]

@bobco85 162693 wrote:

Wait, let me play that back in my head: the traffic engineers concluded that keeping the slip lane was the safer option.
The traffic engineers concluded that keeping the slip lane was the safer option.
The traffic engineers concluded that keeping the slip lane was the safer option.
The traffic engineers…

(ILLOGICAL. ILLOGICAL. ILLOGICAL ARGUMENT OVERLOADING BRAIN. SHUTTING DOWN NOW)

It’s not as cut and dry as it might seem.

You’ve got a T intersection where a huge majority of traffic is turning right. You’ve got a trail crossing parallel to the predominate traffic flow.

You decide to eliminate the slip lane, but to try to accommodate the huge amount of right-turning traffic you allow right on red.

Congratulations, you’ve recreated the Intersection of Doom. Huge amount of right turning traffic which has a green the same time the bikes & peds do + they’re looking left the whole time they have a red for an opening so they don’t see that the light has turned green and a bike has entered the intersection.

Alrighty then, let’s eliminate the right on red for safety. Now you’ve got huge backups of traffic from that huge # of people trying to turn right + you’ve still got major conflict during the green. No problem you say, we’ll add a dedicated bike & ped phase where no traffic gets to go in any direction (a Barnes Dance) and lengthen the green time to eliminate the traffic backup. Awesome – you’ve now lengthened the signal time to the point that a bike or ped who arrives is waiting 2+ minutes for a walk signal, so they give up and take their chances darting across the intersection.

I was skeptical at first, but I’ve come round to leaving the slip lane, but making the island big enough that you can actually safely wait on it + improving the sight lines being the smartest option.

[scoot]

@chris_s 162729 wrote:

Alrighty then, let’s eliminate the right on red for safety. Now you’ve got huge backups of traffic from that huge # of people trying to turn right

In the very short term, yes. But wouldn’t that huge # of drivers soon realize that they have alternatives to Walter Reed, such as Shirlington Road or even 395, thus canceling out any excessive imbalance in travel time?

(i.e. Induced demand works both ways…)

[consularrider]

@Steve O 162691 wrote:

For the record, the Arlington Bicycle Advisory Committee also recommended elimination of the slip lane, but their recommendation was not heeded by traffic engineering.

The traffic engineer’s explanation six years ago involved the turning radius of the school buses and DES trucks that are heavy users of that intersection

[mstone]

@chris_s 162729 wrote:

It’s not as cut and dry as it might seem.

You’ve got a T intersection where a huge majority of traffic is turning right. You’ve got a trail crossing parallel to the predominate traffic flow.

You decide to eliminate the slip lane, but to try to accommodate the huge amount of right-turning traffic you allow right on red.

Congratulations, you’ve recreated the Intersection of Doom. Huge amount of right turning traffic which has a green the same time the bikes & peds do + they’re looking left the whole time they have a red for an opening so they don’t see that the light has turned green and a bike has entered the intersection.

Alrighty then, let’s eliminate the right on red for safety. Now you’ve got huge backups of traffic from that huge # of people trying to turn right + you’ve still got major conflict during the green. No problem you say, we’ll add a dedicated bike & ped phase where no traffic gets to go in any direction (a Barnes Dance) and lengthen the green time to eliminate the traffic backup. Awesome – you’ve now lengthened the signal time to the point that a bike or ped who arrives is waiting 2+ minutes for a walk signal, so they give up and take their chances darting across the intersection.

I was skeptical at first, but I’ve come round to leaving the slip lane, but making the island big enough that you can actually safely wait on it + improving the sight lines being the smartest option.

If they really need a steam of drivers turning right, the smartest option would be a dedicated merge lane for the right turners after the turn, so they wouldn’t have to be looking left for a merge opportunity instead of looking in front of them as they should be. In this case it might even require taking a lane–but safety was the number one priority, right?

[Sunyata]

@consularrider 162731 wrote:

The traffic engineer’s explanation six years ago involved the turning radius of the school buses and DES trucks that are heavy users of that intersection

As someone who both bikes through there occasionally and drives a VERY large piece of equipment through there on a regular basis: ^THIS

It would be incredibly hard to turn the apparatus that I operate (for the county – our maintenance yard and training academy are down on Taylor Street) right from the middle lane. That being said, I do think that enlarging the island is a huge step in the right direction.

[AFHokie]

@Sunyata 162738 wrote:

As someone who both bikes through there occasionally and drives a VERY large piece of equipment through there on a regular basis: ^THIS

It would be incredibly hard to turn the apparatus that I operate (for the county – our maintenance yard and training academy are down on Taylor Street) right from the middle lane. That being said, I do think that enlarging the island is a huge step in the right direction.

I’d add move the trail crossing of the slip lane back to where the new stripes start…there’s now plenty of room for bikes/peds in the closed off lane and drivers shouldn’t be looking left yet that further back

Sent from my SAMSUNG-SM-G930AZ using Tapatalk

[bobco85]

Keeping the slip lane is not safe because it does not slow drivers down as they approach the crosswalk. That is a current problem that other posters have mentioned. Even if the crossing were moved farther from the intersection with the bigger island, the fundamental issue of drivers not yielding remains.

The problem of turning radius is one that has seemingly been solved at other intersections throughout the county, so I think we could easily increase the turning radius of that corner as necessary or increase the width of the right lane so that larger vehicles have room to maneuver.

I think removing the slip lane entirely and converting the now-closed right lane to a right turn only lane that has a dedicated green arrow for the start of the WB Walter Reed Dr green cycle (starts with green left turn arrow) would be the better solution. It doesn’t compare to the Intersection of Doom because drivers are not entering the intersection directly from a high speed interstate off-ramp and there aren’t 2 right turn lanes.

Now, if there were a Four Mile Run Expressway, this would be a different story

[lordofthemark]

City of Alexandria

Prince and Cameron Streets Complete Streets project — Bike lanes completed

Wilkes Street: Trail realigned at Rte 1

Taney Avenue bike lanes stripe· Taney Ave Park trail connection status?

[lordofthemark]

Arlington County

Washington Blvd bike lanes approved. https://www.arlnow.com/2017/04/19/plans-for-washington-blvd-bike-lanes-abandoned/

New green bike lanes on 18th Street east from Eads Street (no link, but I saw them)

Four Mile Run Trail reopened, resurfaced (widened?) between Eads Street and Rte 1.

[CaseyKane50]

@lordofthemark 162747 wrote:

City of Alexandria

Wilkes Street: Trail realigned at Rte 1

Trail realignment has yet to occur. City is waiting for Dominion to relocate a light that is in the path of the planned trail.

[ATTACH=CONFIG]15142[/ATTACH]

[Judd]

@CaseyKane50 162816 wrote:

Trail realignment has yet to occur. City is waiting for Dominion to relocate a light that is in the path of the planned trail.

[ATTACH=CONFIG]15142[/ATTACH]

The one time I wish a car would careen off the road and damage something…

[zsionakides]

@bobco85 162746 wrote:

Keeping the slip lane is not safe because it does not slow drivers down as they approach the crosswalk. That is a current problem that other posters have mentioned. Even if the crossing were moved farther from the intersection with the bigger island, the fundamental issue of drivers not yielding remains.

The problem of turning radius is one that has seemingly been solved at other intersections throughout the county, so I think we could easily increase the turning radius of that corner as necessary or increase the width of the right lane so that larger vehicles have room to maneuver.

I think removing the slip lane entirely and converting the now-closed right lane to a right turn only lane that has a dedicated green arrow for the start of the WB Walter Reed Dr green cycle (starts with green left turn arrow) would be the better solution. It doesn’t compare to the Intersection of Doom because drivers are not entering the intersection directly from a high speed interstate off-ramp and there aren’t 2 right turn lanes.

If we did this, then the intersection would be pretty similar to turning right from 4 Mile Run to Walter Reed where the W&OD is. That’s a safer intersection as most cars are good about being aware for bikes and runners, and know they have to yield right of way.

Right now a considerable amount of traffic coming from Arlington Mill disregards their obligation to yield to pedestrians and bicyclists. The slip lane is a considerable part of that problem.

[Fairlington124]

I believe recalling that the trucks and buses which call at the nearby Trades Center (between Shirlington and the AWLA) were a reason for maintaining the slip lane.

[Greenbelt]

A new trail in Greenbelt bypasses the congested area around Beltway Plaza Mall. This trail connects Branchville Ave (the main access road to Lake Artemesia) with Cherrywood Lane (a main bike route in Greenbelt, which goes past the Metro etc.)

Here’s how it looks as your heading north-ish (toward Greenbelt) from Lake Artemesia. Entrance is by the PG metals scrapyard on the left. Exit is at the newly built (not quite open) ADA ramp at the three-way stop intersection of Cherrywood Lane and Breezewood Drive.

[IMG]https://scontent-iad3-1.xx.fbcdn.net/v/t31.0-8/20045315_1420072338059479_1027645318299731931_o.jpg?oh=b81eabd55c8a6cb5cd02d3d4b52d901e&oe=5A0BFB64[/IMG]
[IMG]https://scontent-iad3-1.xx.fbcdn.net/v/t31.0-8/20121160_1420072288059484_3813434788632744167_o.jpg?oh=5a631461057e8d09b058418254af0c65&oe=5A097BFF[/IMG]
[IMG]https://scontent-iad3-1.xx.fbcdn.net/v/t31.0-8/20117087_1420072248059488_1327320248224141310_o.jpg?oh=6027bc7b2f48c7ad1bff4c71056821b3&oe=5A0C1893[/IMG]
[IMG]https://scontent-iad3-1.xx.fbcdn.net/v/t31.0-8/20116973_1420072191392827_609804701386696153_o.jpg?oh=5815543e22334d52b9aa5d0a17868a36&oe=5A02F0A8[/IMG]

[Author]

Posts