Saturday, November 19, 2011

Bicycle signal detection on Soapstone Dr bike lanes

Randy and David check detector location and sensitivity.
The Soapstone Drive road diet project is nearly finished. Approximately two miles of bike lanes were created when four travel lanes were reduced to two regular travel lanes, bike lanes, and a center turn lane. The bike lanes are striped and a few bike symbols have been painted in the lanes, with several more to be added before the project is complete.

There are three traffic signals within or adjacent to the project, at Lawyers Rd, South Lakes Dr, and Sunrise Valley Dr. At most traffic signals in the county the presence of motor vehicles is detected automatically. As many cyclists know, they don't always detect bicycles. BikeLoudoun asked VDOT about this issue last year and wrote the response in their blog post Why Doesn't the Light Turn Green for Bicyclists?

According to VDOT Regional Operations Maintenance Manager, Mark D. Hagan, "most of our traffic signals in Northern Virginia use what are known as 'inductive loops,' which is a loop of wire located within the pavement with a small electrical charge that creates an electrical field. The electronic device within the control box cabinet looks for an inductance change within that electrical field and triggers a signal that a car, motorcycle or bike is present."

Detectors have been placed in the bike lanes on either side of the traffic signal at Soapstone Dr. and South Lakes Dr. On Saturday VDOT traffic engineer Randy Dittberner and a signal technician from VDOT met David Gibson of Federal Highway Administration to determine the location and sensitivity of the detectors.

The detectors are embedded in the pavement and there's no sign of them on the surface. Thy are located about 5 feet behind the bike lane stop bar. When the bicycle passes over the sensor it is detected and a call is issued for a signal change. However, if 10 seconds passes before the signal changes, the call terminates. In order to ensure the light changes, cyclists need to stop on the sensor. Since the sensor isn't visible, a marking is needed to notify cyclists where to stop.

The Bicycle Detector Pavement Marking is used for this purpose: "A symbol (see Figure 9C-7) may be placed on the pavement indicating the optimum position for a bicyclist to actuate the signal." In the photo above, the bike symbol will be located where the letters "BK" are painted.

To our knowledge, these are the first bike detector markings used in the county. This is progress. Look for them the next time you're riding along Soapstone Dr.

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what does this cost the taxpayer?
The sensor is embedded into the subsurface before the final asphalt layer is added. I doubt that it adds any additional cost since these sensors are used for all vehicles. This one just happens to be for bicycles. There is a small cost associated with adding the bike symbol. In my opinion it's a very small cost when you think that the needs of bicyclists at traffic signals has rarely been considered in the past.
I don't care whether bikes get the green light or not. I care that they are an arrogant bunch of syncophants and ride down Glade and other streets in mobs of six or so across and in a pack. The law is that they are to ride single file down the street. They give drivers the bird whenever anyone honks to draw their pea brains' attention to the fact that they are impeding traffic. They have to be MEN with balls and police themselves because Fairfax county mounties are not going to do anything unless they are 5 feet from where it is happening at the moment it is happening. Thus we have many angry taxpayers who are tired of public officials wiping the butts of these effite snobs.
Anonymous, Many, many motorists disobey the law every time they drive. The next time you are at an intersection, watch motorists' behavior. Most think it's their right not to stop at a stop sign or red light. The law says they will come to a complete stop. Their actions endanger pedestrians, cyclists, and other motorists. Most motorists also think that the speed LIMIT is a minimum and most exceed it. Try driving the speed limit, which I do personally, and watch how many others pass or tailgate. I'm tired of hearing the same old argument that because a group of cyclists acts badly other bicyclists should have no rights. We all need to obey the law.
Why do you justify bad bicyclist behavior *which I can attest I see often exactly as described herein * by bad motorist behavior?

All of the behavior is bad, rude and likely illegal and none of it is any form of justification for anyone.

Please tell the construction company to remove it signs all over the road warning of no pavement markings. The pavement has been marked for weeks. The signs are wrong and unnecessary.

And please ask VDOT to install a left-turn signal on northbound Soapstone at South Lakes at the new turn-only lane.

The road diet did nothing to increase visibility at that intersection and there's already been (yet another) accident because of the bad sight lines and NO street lighting at this still dangerous intersection.
The pavement markings are not complete. At Soapstone and Glade the stripping and other markings need to be finished, and the bicycle symbols in the bike lanes along the entire road need to be added. There are a few in place but more need to be added.

As I said in my earlier comment, we all need to obey the law, and cyclists deserve to get a green signal just like motorists do.
There are many bike riders on Glade and practically 0 on Soapstone, why the bike lanes where not placed on glade where they are needed "as a test" is a mystery to me. As we all know Glade is used as a Bike racers training road; seems to me bike lanes might offer a solution to the growing anger of drivers to the lack of public attention to this issue.
In my opinion bike lanes are not needed on Glade, which is wide enough for bicyclists and motorists to share the lane. There is parking on the road which complicates installing bike lanes. They would have to be installed to the left of the cars, away from the door zone. There are groups of cyclists on one day of the way for a brief period of time that ride on Glade and other roads in Reston. Their impact on motorists has been greatly exaggerated.

One major reason for having bike lanes on Soapstone is the future metro station at Wiehle Ave. With bike lanes on Lawyers Rd and Soapstone, there is now a huge catchment area of people who could ride to the station.

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