https://doi.org/10.1177/0361198118783171 Transportation Research Record 1–10 © National Academy of Sciences: Transportation Research Board 2018 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0361198118783171 journals.sagepub.com/home/trr TRR JOURNAL OF THE TRANSPORTATION RESEARCH BOARD Article In urban areas, traffic calming measures have become a necessity as different types of road users and vehicles inter- act with each other continuously. Traffic calming measures play an important role in traffic safety. Various kinds of traf- fic calming measures used are speed bumps, speed humps, speed cushions, speed tables, and chicanes. Among all, speed humps (and variations such as speed bump, speed table) are the most commonly used. It is mainly used to achieve lower speeds in speed sensitive areas such as schools, parking lots, toll plazas etc. Speed humps have the advantage of being largely self-enforcing and of creating a visual impression, real or imaginary, that speeding is not permitted on a given stretch of the road (1). They are cost-efficient and restrict the number of over-speeding drivers. Assembling and disman- tling speed humps is very quick and they are easy to main- tain. On the other hand, speed humps pose various limitations such as the inconvenience caused to emergency vehicles and discomfort to local residents who frequently use the road. One major problem created by speed bumps is that non- motorized vehicles such as bicyclists suffer severe vibrations while crossing even at slow speeds. To overcome this short- coming, various designs of speed humps with bicycle pass lanes, speed tables with smooth channels, and speed kidney have been introduced (2, 3). The efficacy of these designs is yet to be validated in traffic conditions of developing nations, which have a huge proportion of two-wheelers and do not have proper road discipline. Thus, this study aims to modify a speed bump to make it bicycle friendly and validate its effects through before–after traffic analyses. Literature Review Traffic calming is the combination of mainly physical mea- sures that reduce the negative effects of motor vehicle use, alter driver behavior and improve conditions for non-motor- ized street users (4). Various measures under traffic calming are meant for controlling speed as well as managing traffic flows. In urban areas, the driving speed plays a decisive role in the severity of the crashes. The chances of fatal injury to pedestrians increase from 10% to 75% if the speed of the vehicle causing the crash is increased from 30 to 50 km/h (5). Therefore, the use of traffic calming (speed controlling) measures is unavoidable in urban and residential areas. Variety of measures used include speed humps, raised cross- walks, raised intersections, center islands and chicanes, to name a few (6). Amongst these, speed humps/bumps are the most popular owing to their simplicity as well 783171TRR XX X 10.1177/0361198118783171Transportation Research RecordVasudevan et al research-article 2018 1 Indian Institute of Technology Kanpur, Kanpur, India Corresponding Author: Address correspondence to Vinod Vasudevan: vinodv@iitk.ac.in Design and Evaluation of K-Pass: A Bicycle-Friendly Modification of Speed Bumps Vinod Vasudevan 1 , Aniruddha Rajurkar 1 , Rahul Soni 1 , and Akhil Tiwari 1 Abstract Traffic safety is a major concern across the world. Since speed is a major cause of traffic crashes, various traffic calming measures are used to enhance the safety of the road users in urban areas. Speed humps and bumps are the most widely used traffic calming devices. As a considerable number of bicyclists use the road along with motorized users, it is important to consider them while deploying any traffic calming devices. Studies have shown that bicyclists experience significantly larger discomfort as compared to motorized vehicles while passing over speed humps. In this study, a modification has been proposed to enhance riding comfort of bicyclists without compromising the traffic calming attribute of a speed bump. This modification is named “K-pass.” Analysis of data collected before and after the modification justifies the effectiveness in reducing the discomfort of bicyclists. Over a period of eight months, 70% of the bicyclists chose to use K-pass. Data also revealed that a high proportion of motorized two-wheeler users also used the K-pass at reduced speeds. It is expected that the K-pass will be a useful modification to the existing speed humps and speed bumps in areas where bicycle usage is expected.