Thursday, April 22, 2010

Blanchard Road, Belmont/Cambridge, Massachusetts

Submitted by Paul Carbone

Blanchard Road, which lies on the border of the city of Cambridge and the town of Belmont, is located just west of Fresh Pond and crosses Concord Avenue. Recently Blanchard Road was redesigned to slow down traffic and accommodate bicycles, while still allowing for MBTA buses and a large volume of traffic to use the road.

Blanchard Road was originally intended to be a local road but it has become a popular shortcut route between Belmont and Watertown, and is now more of a collector. Speeds on Blanchard Road were sometimes higher than is suitable for the densely populated residential area that is present on the road. In addition this area has become an increasingly popular place for recreation, especially for bicyclists, with many nearby paths. Local residents also use bicycles to commute to the Alewife MBTA station, which is less than a mile away from Blanchard Road. Additionally, the road is along the route of the 78 and 74 buses from Harvard station. The combination of high speeds and volumes in a residential area and heavy bicycle traffic meant that Blanchard Road was in need of a redesign. There was a need to slow down traffic, while also providing a facility where vehicles would be more mindful of bicyclists and buses could still be accommodated. Within the last year Blanchard Road was revamped with bike lanes or sharrows as well as many traffic calming devices to try and address these needs.

Blanchard Street to the North side of Concord Avenue contains two new major features: a chicane and sharrows along the edge of the road.

The chicane was created by adding a grass bumpout at the intersection of Blanchard Street and S. Normandy Avenue. Signs are posted advising a 25 mph speed through this area. During a short observation of the chicane, it was found to be effective in the immediate area during times when there were vehicles travelling in both directions or vehicles travelling at exceptionally high speeds for this road. However, when there was no opposing traffic, vehicles would encroach over the centerline to maintain speed. In addition, vehicles that did slow down typically sped up shortly after the chicane. Additionally, there is a crosswalk at the location of the chicane and it seems that a median refuge would have been a better use of the extra space that the chicane uses. To more effectively slow traffic down, additional traffic calming devices would be needed.

Blanchard Street in this area is too narrow for dedicated bike lanes, so sharrows were utilized. The sharrows provide experienced bicyclists with recognition but they are not a great option for inexperienced riders, especially with the chicane. However, there is not much room for any other option and sharrows are better than not acknowledging bicycles. Since the northern part of Blanchard Road was completed before the Southern section, the one improvement that is needed is a repainting of the sharrow symbols in the lanes to make them less faded.

To the South side of Concord Ave, Blanchard Street incorporates many new features: small chicanes, a raised intersection/ crosswalk, in-street reflectors, a modern day roundabout, and dedicated bike lanes.

First, just south of Concord Ave there is a small chicane created by shifting the sidewalk widths on both sides of the road. This chicane does not have a huge effect on speed but coupled with the other traffic calming devices, it helps to lower the travel speeds overall.

Also starting just south of the intersection of Blanchard Road and Concord Ave are two one-way bike lanes on the outside of the travel lanes. These bike lanes are a much safer alternative to sharrows and they provide access to Concord Ave, where additional bicycle facilities are present.

A few hundred feet farther down the road there is a raised intersection with an advisory speed of 20 mph. Approaching the intersection there are yield markings and the entire raised intersection is composed of red pavers. This measure appeared to be very effective at slowing down vehicles on Blanchard Road and it also serves as a crosswalk for pedestrians. The design is also easy to travel on for bicycles.

Along the length of the southern portion of Blanchard Road there are in-street reflectors. These reflectors are located along the centerline and between the vehicular lanes and bike lanes. They enhance the visual separation between bicycles and cars as well as opposing lanes. The reflectors also allow the separation to be more visible at night.

Farther down the road, there is a sharp curve. While this was not added, the curve serves as a traffic calming device. Curve signs together with narrower lanes make this an effective way to maintain the slower speeds that the raised intersection brought vehicles to.

Finally, there is a modern day roundabout immediately following the curve. This greatly helps to slow down traffic. The radius of the roundabout is small, but it is large enough for buses to navigate. Approaching the roundabout there is a crosswalk with a median divider that cuts the crosswalk in half. This provides much more protection for pedestrians that need to cross the road. The only area that arose concern was that the bike lanes ended and sharrows were used instead for the roundabout. This roundabout experiences heavy traffic and after providing the increased safety of dedicated bike lanes, it would be ideal to provide a more exclusive bike route through the roundabout.

A local resident waiting at the bus stop was very supportive of the changes that were made on Blanchard Road, and he said that they have made a huge difference in the speed of vehicles traveling on this road. He also said that riding a bicycle feels much safer with the dedicated lanes Individually the improvements may not have been completely effective but as a whole they have done a great job of meeting the needs of the residents.

1 comment:

  1. It's worth noting that this street lies (just barely) in Cambridge, who made the improvements.

    Very good analysis of the many treatments there. Including a comment from a resident is valuable, too.

    I'm curious about bicyclists approaching the roundabout who have to marge into the travel lane - is it an easy merge (say, because cars have had to slow down to the same speed as bikes)? Do drivers yield to bikes, letting them in, or do the bikes get squeezed out?

    US guidelines clearly recommend against bike lanes in a roundabout. Dutch guidelines do too (but there are exceptions), but recommend providing a separate path outside the roundabout if daily traffic exceeds 8,000. I think daily traffic here is probably close to 12,000, so that bikes in the carriageway probably doesn't meet "low stress" criteria.