A report on standardized signage and markings

This memo is in response to Order 9 from the November 7, 2016 City Council Meeting (Awaiting Report Item 16-95), requesting that the City Manager work with the Traffic, Parking, and Transportation Department to make street markings and street signage more ubiquitous to market the rules of the road to the users of all transportation modes and report back on this matter.

The Traffic, Parking, and Transportation Department strives to maintain consistent pavement markings, signals, and signage standards for traffic operations citywide to provide a safe and comfortable roadway environment in Cambridge. Using consistent and understandable traffic control devices is critical to ensure that pedestrians, bicyclists, and drivers understand the rules of the road and how they are expected to operate in specific conditions. Pavement markings and traffic signs play an important role in how we manage our streets, and we are continually looking for opportunities to use these tools most effectively to improve the safety of our transportation system.

For greatest clarity and legibility for users, it is important that our standards are not just consistent citywide, but also that they are consistent with other cities both across Massachusetts and around the country. As such, we use Federal and State guidelines to the greatest extent possible so that all road users recognize and understand the message that is being communicated. Federal standards for signage and striping are provided in the Manual on Uniform Traffic Control Devices (MUTCD), 2009 Edition. https://mutcd.fhwa.dot.gov/kno_2009r1r2.htm as well as the Massachusetts amendments to the MUTCD.

In addition to the guidance provided by the MUTCD, newer trends in transportation for bicycle facilities are guided by the following Federal and State documents:

Page 2 of 4 Massachusetts Department of Transportation (MassDOT) Separated Bike Lane Planning and Design Guide, 2015 http://www.massdot.state.ma.us/highway/DoingBusinessWithUs/ManualsPublicationsForms/Separa tedBikeLanePlanningDesignGuide.aspx National Association of City Transportation Officials (NACTO) Urban Street Design Guide, 2013 http://nacto.org/publication/urban-street-design-guide/ Federal Highway Administration (FHWA) Achieving Multimodal Networks: Applying Flexibility & Reducing Conflicts, 2016 https://www.fhwa.dot.gov/environment/bicycle_pedestrian/publications/multimodal_networks/ In implementing these traffic controls, we strive to find an appropriate balance in how many signs and markings we install, trading off issues such as safety, aesthetics, physical space, and many others.

While most traffic control devices such as crosswalks, parking signs, traffic signals, etc. in Cambridge have been standardized for many years, the evolving state of the practice—particularly for bicycle facilities—has resulted in many new forms of traffic control. As we work to implement these new traffic controls, we continue to seek that appropriate balance, communicating key messages without creating confusion or “sign clutter” that can lead to problems.

Based on our review of the guidance noted above, as well as the input we have received from road users, we are planning to proactively and strategically incorporate the following traffic control elements into both upcoming bicycle facility implementation projects and existing facilities through ongoing maintenance and upgrades:  Green intersection crossing markings

• These markings provide guidance for cyclists through an intersection while also alerting both drivers and cyclists to watch for conflicting movements as they maneuver through an intersection. Page 3 of 4  Two stage turn queue box
• These markings provide a designated location for cyclists to move right at a signalized intersection and wait for the cross-street green signal indication. This allows cyclists to make a left turn without conflicting with parallel through traffic.  Bike boxes
• Bike boxes provide an advance stop bar for cyclists at signalized intersections, allowing them to line up ahead of parallel vehicular traffic to ensure visibility and allow for turns during the green signal phase.  Green shared lane markings
• Green-backed shared lane markings are installed at key locations where limited roadway width or other factors require that bicycles and vehicles share the lane on short segments connecting between exclusive bicycle facilities.  Bus stop conflict zones
• Green bike lane markings adjacent to heavily used MBTA bus stops alert both cyclists and bus drivers to be aware of potential conflicts. Page 4 of 4  Bike signals
• Bike signals are typically implemented at existing traffic signals as part of the installation of separated bike lanes along a corridor. Bike signals may be timed in several different ways:  Lead bicycle interval: Similar to and typically concurrent to a lead pedestrian interval, allowing bicycles the chance to enter the intersection prior to vehicles to increase visibility.  Protected bike phase: In locations where heavy turn conflicts or unusual bike movements exist, signal phasing may provide for protected movements through either protected vehicle turn phases or exclusive bike phases.  Bike intersection signage
• Turning Traffic Yield to Pedestrians and Bikes – Installed at locations where turning vehicle conflicts exist
• Except Bikes – Sign placards provide exceptions for bikes for No Turn on Red restrictions and one-way/Do Not Enter restrictions where bicycles may safely make maneuvers that vehicles are not permitted to make.

It is important to note that the use of green pavement treatments and shared lane markings is limited to bicycle intersection features, conflict zones, and key bicycle connections, so as to enhance conspicuity, compliance, and visibility in these key locations. At this point, we do not intend to paint entire segments of bicycle lanes green or deploy shared lane markings on the majority of streets, since such a strategy would reduce the ability to effectively highlight areas of conflict and key connections.