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4 Introduction Scope of Work The objective of NCHRP Project 08-102, Bicyclist Facility Preferences and Effects on Increasing Bicycle Trips, is to understand how both current and potential cyclists respond to different types of bicycling facilities, thus facilitating a quantification of demand that includes both induced trips and trips shifted to the cycling mode. To meet this objective, the research team con- ducted comprehensive data collection and analysis to improve the understanding of how people make choices about daily travel (referring to the adoption, or lack thereof, of active modes of transportation), focusing on a region of the United States where cycling for transportation is just emerging. The research presented in this report addresses several key questions: â¢ What are the relative preferences of current and potential bicycle users for different types of bicycle facilities? â¢ How do such preferences vary by demographic characteristics, cyclist experience, and community environments? â¢ What is the relative effectiveness of different types of bicycle facilities for attracting new bicycle users and for increasing bicycle travel by existing bicycle users in different environments? This study offers a unique opportunity to explore the factors affecting the travel behavior of different types of users, and the way in which new infrastructure projects affect the cycling choices of residents in the affected areas. In contrast to previous research that has predominantly been conducted in communities where cycling is widely accepted and automobile drivers are conditioned to the presence of cyclists, this project focuses on communities where cycling for transportation is relatively new. Accordingly, the data collection was designed to cover several neighborhoods carefully chosen to include various predominant land uses and planned infrastructure in regions of the United States where bicycling is not (currently) widespread. Past Literature on Types of Cycling Facilities Before beginning this project, a search of the literature was conducted using primarily the Transportation Research Boardâs Transportation Research International database. Prefer- ence was given to papers written in English with American data, though some relevant English language papers with international data were also reviewed. This section contains a review of the literature applicable to bicycling facilities and the perceptions, preferences, and use of such facilities by potential and current cyclists. C H A P T E R 1
Introduction 5 Studies of infrastructure treatments such as bicycle lanes, shared lanes, off-street paths, bicycle boulevards, cycletracks, bike boxes, traffic signal phases, traffic calming, car-free zones, and complete streets have shown that a significant increase in bicyclists can be achieved by providing facilities for safe riding (Pucher et al. 2010). On the other hand, Handy et al. (2014) noted that studies have often measured bicycling facilities in simplistic terms, such as miles of bicycle lanes or of all types of bicycle facilities, without differentiation of facility type (e.g., Dill and Carr 2003; Cleaveland and Douma 2008; Krizek et al. 2009a; Schoner and Levinson 2014). Other analyses have been limited only to a single facility type such as a traditional bike lane (Parker et al. 2013) or off-street bicycle and multi-use paths (Jones 2012; Downward and Rasciute 2015; Heinen et al. 2015; Rissel et al. 2015; Sahlqvist et al. 2015). Results regarding the relative impact on different facility types have been inconsistent. Buehler and Pucher (2012) found no significant difference in cities throughout the United States between the effects of on-street bike lanes and off-street trails, though both have a positive correlation with cycling. Hankey et al. (2012) and Moudon et al. (2005) found a strong correla- tion of cycling rates with off-street trails but not bike lanes. However, Krizek and Johnson (2006) found a significant impact in the disaggregate from on-street lanes but not off-street trails. Dill and Voros (2007) studied the difference between objective measures of bicycling facilities and subjective perceptions of the availability of bicycling facilities, and found that while perceptions of availability were significant, objective measures of either on-street or off-street facilities did not have a significant effect on cycling rates. Dill and Carr (2003) found the total availability of facilities and bicycling rates were corre- lated, but facilities alone were not likely to increase cycling. Parkin et al. (2008) pointed out that reasonable increases in bicycle facilities alone generated only a modest increase in cycling rates, and that forecasts from different studies varied based on approach type and other unmeasured differences in environments and culture. Ma and Dill (2015) also reported that inconsistencies may be the result of the different interaction between objective and perceptive infrastructure measures, especially visibility (Ma and Dill 2015; Sahlqvist et al. 2015). Dill (2009, S106) stated that a ânetwork of different types of infrastructure appears necessary to attract new people to bicycling. Simply adding bike lanes to all new major roads is unlikely to achieve high rates of bicycling.â Protected/separated facilities are usually the preferred choice, particularly through intersections (Burbidge and Shea 2018). Evidence on preferences for different facilities (e.g., bike lanes versus paths versus cycle- tracks) has largely come from studies of route choice. However, these studies have primarily been restricted to existing cyclistsâ preferences rather than the ability of such facilities to entice new cyclists. Dill and Gliebe (2008) used GPS data to compare cyclistsâ chosen routes against the shortest path. The most important factor in choosing a route was stated to be minimum time, followed by low traffic volume and presence of a bike lane. Additionally, riders spent more time on bicycle facilities and low-traffic streets than predicted by the shortest route, and the deviation from shortest route increased with length of trip. Broach et al. (2010) extended the study by Dill and Gliebe (2008) to develop a multivariate discrete choice model of bike route choice. (The model, used to predict the marginal utilities of different attributes for cyclists in Portland, is being incorporated into the Portland regional travel demand model.) The study showed that bike lanes were preferred in streets with high traffic, but bike lanes did not add any separate value to the cyclists by themselves. Although Broach et al. (2010) had a solid methodology, the results may not be applicable to places that lack the bike infrastructure Portland has. The study also failed to differentiate between different types of cyclists, which has been shown to have an impact on route choice (Pucher and Buehler 2008).
6 Bicyclist Facility Preferences and Effects on Increasing Bicycle Trips Studies of route preferences among potential cyclists have been primarily limited to stated preference studies. The drawback of stated preference surveys is that they are weak predictors of behavior (Klobucar and Fricker 2007). Results from stated preference studies indicate that potential users report being more likely to cycle with separated facilities (Parkin et al. 2008; dellâOlio et al. 2014). A stated preference study in Canada found that users view cycling in mixed traffic as more onerous than in bike lanes or on bike paths, though less so for those with higher confidence levels (Hunt and Abraham 2007). Sanders (2014) used a stated preference study to analyze the preferences of noncyclists as well as current cyclists. Barrier-separated facilities (also referred to as separated bike lanes or cycletracks) were consistently identified by both groups as a comfortable alternative; striped bike lanes were generally viewed as beneficial because they provided cyclists with predictability and legitimacy, though they did not consistently increase perceived comfort. In a study investigating the factors associated with cyclistsâ choice between available facilities, Kang and Fricker (2013) found that off-street paths were more attractive than bike lanes. The literature referenced in this section gives strong evidence of a positive relationship between the presence of bicycle facilities and the frequency of bicycle trips. However, there is a demonstrated need for research regarding the more granular details that may be contribut- ing to the inconsistencies referenced in the literature. The research in this NCHRP project was designed to meet several of these gaps, namely (1) relating bicycle facility effectiveness to bicycle facility type and roadway characteristics, and (2) including both current and potential cyclists.