Aya Kojima

Does Silence Mean Agreement?: Understanding the Silent Group in Neighborhood Traffic Calming Surveys

The decline of response rates in attitude surveys and the nonparticipation of residents are big issues in decision-making processes for transportation planning. The existence of individuals who do not state their opinions, the silent group, disrupts smooth consensus-building processes. It is often claimed that the silent group or so-called silent majority relies on policy makers or proposed plans. This research analyzes the silent groups character in a traffic calming project conducted in a residential area. To understand the silent groups level of awareness, attitude, and preference would help identify better ways of including them in planning processes in the future. Data obtained from questionnaire surveys were used for this analysis. Nonrespondents to the surveys were defined as the silent group. First, the difference of opinions between the silent group and the nonsilent group was investigated. The result showed that the silent group was less aware of the traffic situation in the area and did not easily agree with the proposed plans. Second, the reasons for the silent groups attitude were analyzed. The result suggested that the silent group members felt less danger on roads near their houses, so they do not recognize the traffic situation of the whole neighborhood as serious. Because of the lack of awareness, the group tended to refuse questionnaire surveys. Moreover, the logistic regression analysis concluded that the silent group was less involved with survey topics that dealt with specific traffic problems and countermeasures.

Impact of pavement type on speed behavior of turning vehicles at crosswalk of a signalized intersection: Brick and red color

ABSTRACT Left- and right-turning vehicles are allowed to make a turn through the crosswalk allocated for pedestrians to cross the road safely. When drivers share this space with pedestrians, they are expected to travel at a low or near-walking speed. Before approaching the crosswalk, left- and right-turn drivers must adapt their speed so as to not endanger the pedestrians. This article presents a study comparing the effectiveness of brick and red-colored pavement on changing the speed of the driver when they make a turn through the crosswalk at a signalized intersection. Three intersections with different pavement design scenarios (no pavement design, brick pavement, and red-colored pavement) were selected for the field study. The speed at three situations—free flow condition, at yellow onset, and when accepting the gap with a pedestrian—were analyzed to evaluate the speed behavior. This data were analyzed using multiple linear regression. Results show a positive effect of brick pavement on the crosswalk on reducing a drivers speed in left and right turns.

Intelligent Rat-Runners: Impact of Car Navigation Systems on Safety of Residential Roads

The authors investigated the phenomenon of “intelligent rat-runners”—that is, road drivers that use car navigation systems to drive through residential areas in order to avoid congested traffic on arterial roads. A nationwide questionnaire survey revealed that some of such drivers, as a result of having to look at the displays of their navigation systems, have had experiences that could have resulted in serious accidents. A driving experiment conducted showed that drivers with access to information about narrow streets and route guidance through their navigation systems have a greater tendency to avoid congested arterial roads by turning into residential areas.

INVESTIGATION ON NORTH AMERICAN TRAFFIC CALMING DEVICE SELECTION PRACTICES

Traffic calming provides a process for identifying and addressing existing problems related to speeding, excessive traffic volume, and pedestrian safety concerns on residential streets. Although several traffic calming devices have been installed in Asian countries for example in Japan and Korea; they have no distinct and methodical process for the device selection. The aim of this research is to illustrate a comprehensive review of North American traffic calming device selection process practices. The aim is to establish traffic calming device selection process guiding principles to be introduced in Japan. This research reveals that speeding is the most significant issue for installing a traffic calming device. The result explores that community support is the most important factor for the selection of a traffic calming device. The result shows that speed humps and speed tables or raised crosswalks are the most widely practiced devices.