Monday, August 16, 2010

New Bike Lanes

The City of Laurel is in the initial phase of implementing its Bikeway Masterplan.  As part of this phase, the City has installed their inaugural on-street bike lanes.  The lanes shown below are on 4th Street from Talbott to Montgomery Street.  This segment is one-way only with on-street parking on both sides.  The bike lane has been installed on the left side of the street to reduce the likelihood of bicyclists getting "doored."  The next set of on-street bike lanes to be installed will be along 4th Street from Gude Park to Greenhill Drive.


  1. It's been a few days since they painted the bike lane, but there are no painted bike symbols or signs that I've noticed yet.

  2. Key concept for bicyclists: The Fourth Street bike lane is One Way Only from Talbott Street to Montgomery Street; this means to ride with and not against the flow of traffic.

  3. this a problem?
    I thought that the bike lane arrows were pretty clear, along with the all the one-way street signs.

  4. Now if only I didn't feel like someone was going to run me down on Montgomery St going 45 miles an hour! (Out here towards 10th where the stop signs run out.)

  5. I am very impressed with both this project and the government transparency that you are showing here. I have a few comments/questions about different facilities but will limit myself to bike lanes.

    The AASHTO guidelines seem to be for at least 5 feet from the curb, but the MD SHA guidelines are for 5 feet from the edge of the gutter/pavement, which would make the lane a foot or so wider. Similarly, where there is parking, the Maryland SHA guidance is that the right side of the bike lane should be 8 feet from edge of the pavement. What is your design standard?

    On a related note, parts of bike lanes are usually within the door zones of parked vehicles. The SHA guidance mentions (without mandating) some alternate pavement markings to indicate the door zone and thereby encourage the cyclist to ride on the left side (rather than the middle) of the bike lane. Have you considered these options? With a 6.5-foot SUV, 3.5 foot door, parked at the edge of the pavement, the door zone extends 10 feet from the edge of the pavement (11 feet from the curb), meaning that the cycle tire needs to be 11 feet from the edge of the pavement (12 feet from the curb) to be out of the door zone of such an SUV. A standard mini-SUV would only give you an extra foot in this scenario.

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  7. Jim,
    Thank you for the compliments! It's great to hear positive feedback from residents. It sounds like you know a fair bit about design guidelines - feel free to be critical, if you think we're doing something wrong. On the same token, if you're interested in details about future lanes, etc., let me know.

    The existing bike lane on 4th street from Talbot to Montgomery is 5 feet wide with the left line, 7.5 feet from the curb face. We would like to have gone farther out, but the current setup provides 17.5 feet leftover for parking on the right side and a travel lane. This layout was based on the following:
    1. This segment of 4th street has an ADT of only 1800.
    2. The average vehicle speed is 24mph, with only 14 cars/day exceeding 35mph.
    3. On-street parking is available on both sides of the one-way street, with the utilization rate varying between 0% and 50%.
    4. To reduce the odds of dooring, we placed the lane on the passenger side.

    If the volumes and speeds on this segment were not this low, we would not have placed lanes here at all.

    To answer your other question, we used AASHTO guidelines along with good old-fashioned engineering judgment. Our bike lanes are/will be 5 feet minimum. But on roads that have higher volumes, we will exceed that. For example, the next set of bike lanes along 4th street, between Greenhill and Cherry, will be six feet wide on the southbound side (with a 11' travel lane). This is because this section of 4th street sees about 7,000 cars per day - much more than the part of 4th street on the north side of town. The north side of 4th street in this segment will have an 8 foot parking lanes and a 5' bike lane with a 11 foot travel lane (see the blog post from 1/5/2010 for more details). This segment has a parking utilization rate of 0% now, but who knows what the next incantation of Laurel Mall will bring.

    We consider many factors in choosing the location and size of bike lanes. In addition to AASHTO, we look at on-street parking utilization; road condition; curb radii at intersections; # of driveways; vehicle volumes; vehicle average speed; number of "excessive" speeders; vehicle travel lane widths; vehicle types (e.g. # of large trucks); and alternative routes.

  8. Bryon,
    Thank you for your detailed reply, and I ope that my comments do not seem unduly critical. I am in a learning mode, and if I say "why don't you do X" there may be a good reason that I don't know about.
    The idea of a left side bike lane seems innovative. Is there research to back up your hypothesis that it is safer, or is this bike lane an experiment? Common sense tells us that there are far fewer door openings from the right side of the car. On the other hand, passengers are less likely to look for traffic than a driver who has been parallel parking. Also, if a car pulls out of a parking space, the bike lane is in the blind spot. So a priori it is hard to know which of these hazards is greater.
    I think my main suggestion here is to try to mark the door zones in the bike lanes. This is useful not only for a given lane but for educating cyclists about the concept. Where the parking lane is 7.5 feet from the curb, you may find that some cars barely fit within the line since there is no requirement to park your car in the gutter and doing so may cause an opening door to hit the ground. So maybe the door zone goes 3-3.5 feet into the bike lane. But since many cyclists tend to adjust their front tire rather than body to a lane marking, probably all but one foot is in the door zone, in this case.
    Not only does marking a 4 foot door zone warn cyclists, but it also helps to inform the driver about why the cyclist is riding on one side of the bike lane instead of the middle. And in the case of the left side bike lane, riding along the right edge also reduces the hazard from a car pulling out of the parking space.
    There may be an ambiguous PR effect from marking the door zones. You can be sure that doing so would win you rave reviews from cyclists throughout the area and perhaps the state. On the other hand, novice cyclists and noncyclists that don't know about door zones might be annoyed that there is not as much space as they thought.

  9. Jim,
    We welcome all forms of criticism, here. So, don't hesitate to put your two cents in.
    I don’t know if a left side bike lane is novel or innovative; it just seemed to be an appropriate use here. We had an opportunity to put the lane on either side; and, given the large drop-off in vehicle volume on 4th street where the lanes are, we deemed the left side to be safer overall.

    I understand your concern about the door zone. I’m hesitant to attempt much in the way of any experimental markings, given that these are the first bike lanes ever installed in the City. If the on-street parking was fully utilized, day and night, we would not have installed the lanes at all here. It would have been too much of a hazard. In future installations, we will look at increasing the bike lane width and adjusting where the bike symbol/arrow are located within the lane.