Tuesday, August 30, 2011

Bike Sharrows on Laurel Lakes Ave

As part of the City's Bike Masterplan, Laurel Lakes Avenue and Cypress Street were designated as preferred Bike Routes through the City.  As shown below, both Streets were marked with sharrows and signed as Bike Routes.

Bike Guide sign on Cypress, directing cyclists onto Laurel Lakes Ave for access to points south on Route 1.

Sharrows on Laurel Lakes Ave. Sharrows are located such that cyclists won't be doored by parked cars, yet motorists can still easily maneuver around them, if needed.
These two streets bring the City a little closer to having a complete north-south route the full length of the City, providing access to the commercial Route 1 corridor without requiring cyclists to actually ride on Route 1.

Thursday, August 25, 2011

Hiker-Biker Trail on Van Dusen

Contractors for the City of Laurel are putting the finishing touches on an 8-ft wide trail along Van Dusen Road, from MD 198 to North Arbory Court. Here is what the heavily-worn area looked like before:
Van Dusen, before the new hiker-biker trail
Here is what the upgrade - already lined with shade trees - looks like now:
New 8' sidewalk along Van Dusen Road
Comments from passers-by have been overwhelmingly positive!

Tuesday, August 23, 2011

Yes, that was an earthquake in Laurel

But no, it didn't stop ongoing pedestrian and bike projects around town.  Currently, there are two projects underway.  The first is the marking and signing of Laurel Lakes Ave as a designated bike route.  The second project is the installation of a new 8' wide hiker bike trail along Van Dusen Road.  More on both of these important projects to follow.

Thursday, August 11, 2011

Bike Box

This is a photo of Laurel's first intersection bike box.  It was installed with the Cypress Street bike lanes.
Left-turn Bike Box on Eastbound Cypress at Mulberry
The left-turn bike box provides a safe area for cyclists to wait out approaching traffic from westbound Cypress, without fear of being rear-ended by motorists behind them.  The sketch below shows this a bit more clearly.
Sketch showing the two ways that a cyclist can turn left onto Mulberry from Cypress
From the sketch above, an eastbound cyclist traveling in the full lane of Cypress Street can make a quick and easy left turn onto Mulberry* (solid green line) assuming there is no westbound traffic on Cypress.  If there is westbound traffic, the cyclist must wait (like any vehicle) in the intersection until westbound traffic has cleared (dotted green line).  The box delineates a safe area where cyclists are protected from westbound traffic heading toward them, as well as from eastbound traffic coming up behind them.

*Bike lanes will be installed on Mulberry as part of that street's Capital Improvement Project, currently slated to begin next spring.

Bike Lanes on Cypress Street

New bike lanes have been installed on Cypress Street from Oxford Drive to Mulberry Street.  The bike lanes are 6 feet wide.  8-ft parking lanes have been delineated, as well.
New Bike Lanes on both sides of Cypress St.
Because Cypress Street is a collector road for the Vistas, the Tiers, Oak Pointe, as well as the Wellington neighborhoods, it sees a good deal of vehicle traffic; so separating out the bike lanes for this short stretch provides for a safer biking trip.

Wednesday, August 3, 2011

Using Traffic Counters to Target Speeders

Typically, when DPW puts out a traffic counter, we end up with data that provides an overall speed profile, something similar to this:

Typical Speed profile for a road
By itself, this chart gives you high-level data such as average speeds, and percentage of speeders.  While this data is useful in determining if a road has an overall speeding problem, it doesn't provide the micro-level details that tells you if a problem exists during certain times.  For example, last year we presented speed data to residents on Main Street that showed that, on a relative basis, instances of speeding were low.  However, the data didn't break down the speed distribution as a function of time-of-day.  For example: what if all the speeding occurred at night? Or maybe they're all morning commuters?
To try and resolve this, DPW has a borrowed a new counter for the summer that outputs more manageable data that can be graphed into something like this:
The 3-D graph above shows how the speed distribution varies throughout the day.  In the above street, for example, we can see that there is a spike of speeding in the 7:00 hour and the 8:00 hour - meaning that these likely are morning commuters exiting the neighborhood.
Also, we can drill down and see if there are individuals that may speed at the same time every day.
The above graph is a scatterplot of all the vehicles going over 30mph, broken down by time-of-day and by day-of-week.  From this data, we can see that if there are speeders who speed every day at roughly the same time.  Of course, there's no guarantee that it is the same driver, but the data still provides the opportunity for:
  • Selective and efficient radar enforcement; using radar enforcement only when the data shows it to be useful. 
  • Micro-targeting speeders using radar enforcement on small time intervals to target likely repeat offenders.