Nudging motorists to respect bike commuters on the road

by Vince Nieva, Research Advisor, Cities & Behavioral Economics | 27 September 20201

10-minute read for national and local government officials, non-governmental organizations, development agencies, active mobility advocates, and problem-solvers

The COVID-19 pandemic in the Philippines has led to stringent community quarantine protocols and restrictions on public transportation operations. This has, in turn, significantly affected the mobility of Filipinos, particularly that of skeletal workers and frontliners. This has resulted in some Filipinos getting forced to walk long distances to get to work, while many others have started using bicycles as their primary mode of transportation, which has led to the rise of new bikers on the road.

On August 5, it has been reported by Metro Manila Development Authority (MMDA) Chief Col. Edison “Bong” Nebrija on TV Patrol that there were at least 10,000 bike commuters along Metro Manila’s major roads during the Modified Enhanced Community Quarantine (MECQ). The sheer number of bike commuters under the 'new normal' presents an opportunity to promote bike commuting as a norm that can nudge motorists towards responsible driving behavior. One suggested method of communicating such norms is through the effective use of signages as traffic control devices.

Photo of Col. Bong Nebrija's statement on the number of bike commuters during the MECQ, as reported by ABS-CBN TV Patrol (source: Cycling Matters Facebook page)

Evaluating Traffic Control Devices by Design

Hess and Peterson (2015)2 of North Carolina State University undertook a study that assessed three signages that are used in the United States to convey the message which puts priority on cyclists on the road. The authors evaluated the following signages based on (a) design principles and (b) pragmatic grounds, and they compared the way motorists understood the three signages, relative to unsigned roadways:

1. "Share The Road” signage

2. “Bicycles May Use Full Lane” signage

3. Shared Lane Markings or sharrows

Bicycle-related traffic control devices. From left to right, “Share the Road” (Manual on Uniform Traffic Control Devices W11-1 upper plaque plus W16-1 lower) and “Bicycles May Use Full Lane” (R4-11) signage; Shared Lane Markings (sharrows) are painted on the roadway pavement (source: US Departmant of Transportation-Federal Highway Administration3)

Based on survey responses, Hess and Peterson (2015) argue that the “Bicycles May Use Full Lane” signage is “the most comprehensible traffic control device” in terms of getting motorists to respect bike commuters on the road. After analyzing the responses on their questionnaires, the authors made the following assessment:

“In almost every case, on 2- and 4-lane roadways, respondents who saw “Bicycle May Use Full Lane” signage were significantly more likely than those who saw no signage to agree that bicyclists are permitted in the center of the lane, do not have to move right to allow motorists to pass within the same lane, that motorists should wait for a break in traffic before passing in the adjacent lane, and that bicyclists are safe in the travel lane.”4

On the other hand, “Share the Road” signage provided “no additional comprehension compared to an unsigned roadway,”5 while sharrows showed statistically significant differences from unsigned roadways in some cases but not others (Hess & Peterson, 2015). This shows that the responses of road users towards bike commuters between a roadway with no traffic control device and those traffic control devices would depend on the norms that already exist on those roads.

From Design to Norms: Dynamics in Car-Centric Cities

Although the authors’ discussion among the three signages revolved around evaluating the consistency of their results with existing sign design principles and guidelines, their research provides a better understanding of norms as factors that shape road behavior. This is because unsigned roadways suggest the default behavior that road users have with regard to bicyclists on the road.

As the context of this experiment revolved around traffic control devices in the United States, a similar study can be undertaken in the Philippines. As a starting point, it would be good to note that similar dynamics between motorists and bike commuters are likewise shared among roads and streets in Philippine cities. Like most American cities, Philippine cities have designed their roads with cars in mind. Prior to COVID-19, dedicated bus lanes and protected bike lanes were practically non-existent in most cities.

However, with the rising popularity of bike commuting there is plenty of room to visibly nudge motorists to consider bike commuters as default road users. Hess and Peterson (2015) have suggested that combining the “Bicycles May Use Full Lane” and sharrows will help increase comprehensibility of bicyclists’ rights on the road for motorists. The combination of these two traffic control devices involve nudges that use both concepts of social norms and priming.

Traffic Control Devices as Nudges: Norms and Priming

Norms have a strong effect on human behavior as they define what is socially acceptable. People almost always go with the default set of options, whether we recognize it or not.3 In terms of norms, the use of the “Bicycles May Use Full Lane” signage would inform motorists on what to do when dealing with bike commuters in the middle of the road. The sheer number of bike commuters in the 'new normal' would help support the norm conveyed by the signage. This would also provide local government units (LGUs) with complementary options on roads that are either too narrow for or lacking in protected bike lanes.

On the other hand, the introduction of sharrows in the middle of the road, together with the “Bicycles May Use Full Lane” signage would expose motorists to the words and figures of bicycles, which could subconsciously ingrain the idea of bicycles as part of the New Normal.6 This leverages priming, which refers to the use of certain cues through certain sights, words or sensations in order to convey useful information. 7

This proposition can be further validated by implementing a similar experimental design and survey among motorists in the Philippines to evaluate various signages in terms of impact on comprehension and perceptions of safety, among others. Building on insights from behavioral economics, key agencies like the Metro Manila Development Authority (MMDA) can initiate a study to empirically measure the effectiveness of nudge interventions across various signages.

National and local governments and their partners can make proactive assessments on traffic control devices as a way not only to promote active mobility, but also to slow down our streets. Doing so not only supports our bike commuting frontliners, but this also helps make our roads safer in the long run.

1Article cover photo by Masjid Pogung Dalangan on Unsplash
2, 3, 4 Hess, G., & Peterson, M. N., 2015. “Bicycles may use full lane” signage communicates US roadway rules and increases perception of safety. PloS one, 10 (8), e0136973. doi: 10.1371/journal.pone.0136973. Available: Accessed 6 September 2020. 5US Departmant of Transportation-Federal Highway Administration., 2012. Manual on Uniform Traffic Control Devices for Streets and Highways, 2009 Edition, Including Revisions 1 & 2 dated May 2012. Available: 6, 7 Dolan, P., Hallsworth, M., Halpern, D., King, D., Vlaev, I., 2010. Mindspace: Influencing Behaviour through Public Policy. The Institute for Government and Cabinet Office, London.