Transportation Deployment Casebook/2014/Dedicated Bikeway Facilities

Introduction

Cycling as a mode of transportation has been a popular transportation mode since it's invention in the late 1800’s. As of 2003, there were just over a billion bicycles worldwide, nearly twice the number of automobiles across the world. With bicycling serving as an intermediate mode of transportation between walking and motorized transportation, providing dedicated space for bicycles to operate without being infringed upon by automobile traffic and without putting pedestrians in danger is an important idea that has started to help guide how bicycle infrastructure is being constructed across the country. Dedicated bikeways are sometimes called cycle tracks or bike-paths and can take many different forms; some are one-way and separated from traffic with bollards, others are elevated from traffic, and others are two-way and separated from traffic with a row of parking. These are just some of the many forms which dedicated bikeways take but the main concept behind this kind of bicycle facility is that bicycle traffic is physically separated from automobile traffic by a physical barrier of some kind such as parking lanes, bollards, planters, or a grade separation of some kind. These are different from multi-use paths, which are generally used for recreational purposes and do not have interaction with auto traffic of any kind. Often times these dedicated bikeways are differentiated from the rest of the road through the use of different paving types, such as bricks or paving stones, or through the use of a colored paint, usually either green or blue.

Qualitative Analysis

Mode Description

According to the National Association of City Transportation Officials a dedicated bikeway (Cycle Track) is, "an exclusive bike facility that combines the user experience of a separated path with the on-street infrastructure of a conventional bike lane. A cycle track is physically separated from motor traffic and distinct from the sidewalk. Cycle tracks have different forms but all share common elements—they provide space that is intended to be exclusively or primarily used for bicycles, and are separated from motor vehicle travel lanes, parking lanes, and sidewalks. In situations where on-street parking is allowed cycle tracks are located to the curb-side of the parking (in contrast to bike lanes)".

The Scene

The reason for this kind of infrastructure being implemented are the enormous real and perceived benefits of safety for bicyclists, as well as both pedestrians and drivers to a lesser degree. By separating all three modes into different parts of a street, the interaction between these modes is minimized and thus the chances for multi-modal accidents occurring are greatly reduced. This kind of infrastructure is often seen as a better and safer alternative to bike lanes, which do not physically separate cyclists from automobile traffic but instead rely on a painted line to prevent a mixing of modes. In some cases there is not a proper amount of space available for a dedicated bikeway to be implemented and a bike lane becomes the necessary option. Additionally, because this kind of infrastructure is often more costly than bike lanes, bicycle ridership in the area must be high enough to warrant the construction of a new dedicated bikeway. In the case that ridership is determined to be high enough and there is enough space to accommodate the new dedicated bikeway facility, this is often the best and safest kind of infrastructure to pursue. The ideal markets for this kind of infrastructure are areas of a city which either have high levels of bicycle ridership, available space for a dedicated bikeway, or political will to build this kind of infrastructure. Due to the nature of bicycling in many American cities, and the overall dearth of proper cycling facilities, when new dedicated bikeway facilities are constructed the ridership level observed along that corridor often increases to a great degree.

Invention

This kind of bicycle infrastructure has been around almost as long as the bicycle itself, with the first dedicated bikeway in America being constructed in New York City running 2.10 miles along Eastern Parkway, from Washington Avenue to Ralph Street, in 1874. A much longer bikeway was constructed in 1897 connecting Pasadena, CA and Los Angeles, CA. This bikeway was nine miles in length, had electric lights to light the way in the night-time, and cost just fifteen cents to ride from one end to the other. This bikeway proved to be unsuccessful and eventually became the site of the Arroyo Seco Parkway. Around the same time, other dedicated bikeways were constructed in Germany, the Netherlands, and the United Kingdom. The first dedicated bikeway constructed in Germany was built in Bremen in 1887 and Hannover in 1889. Although a few dedicated bikeways were constructed in the UK, the Cyclists’ Touring Club (CTC) came out in vehement opposition to dedicated bikeway facilities because they were seen as inferior to roads for automobiles. Due to this opposition, dedicated bikeways in the UK were not constructed again until the 1970’s when interest in this kind of facility came back in vogue.

Early Market Development

As stated previously, the reasoning for constructing this kind of bicycling infrastructure is to separate modes by their respective speeds and to reduce the intermixing of pedestrians, bicycles, and automobiles. Prior to the invention of this form of bicycle infrastructure in the late 1800’s pedestrians, bicycles, and automobiles were usually mixed in traffic which caused the roads to become very chaotic. While this kind of bicycle infrastructure has been around for over 100 years, in the United States it was not until the 1970s that construction of these facilities became to increase in any measurable way. In other countries such as the Netherlands, where dedicated bikeways have been constructed en masse across the country for decades, the catalyst for building this kind of infrastructure was a high rate of child deaths due automobiles. In the early 1970’s, a campaign called Stop de Kindermoord (Stop the Child-Murder) which used the high rate of child deaths caused by automobiles as a rallying cry to change the transportation infrastructure was successful in forcing Dutch politicians to restrict automobile use in cities and to focus on providing alternative modes of travel. By constructing vast networks of safe and convenient dedicated bikeways, the Netherlands was able to offer an attractive alternative to driving all across the country over the following decades. While this was the catalyst for the Netherlands to begin to construct dedicated bikeways, a different catalyst has been required in the American context.

The Role of Policy in Birthing Phase

A recent increase in the level of bicycling across the United States has caused an increase in the investment in bicycling infrastructure. This increase has come about due to a number of factors including a push to reduce greenhouse gas emissions, a mild “back to the city” movement, and a need to promote healthy living lifestyles across the country. These factors, as well as some others, have created an increase in bicycling activity and thus an increased demand for good, safe, and convenient bicycling facilities. In an effort to not only create these kinds of facilities but also to promote bicycling with populations who would not be inclined to cycle in mixed traffic such as women, children, and the elderly, dedicated bikeways have started to be constructed at an increasing rate in cities across the United States.

This new rise in construction of bicycling facilities is mostly due to an increasing amount of available funds for construction of new bicycling facilities. Although there was a push for more bicycling facilities in the 1970’s, very few new facilities were constructed thanks to the lack of funding available specifically for bicycle facilities. However, in 1991 following pressure from bicycling advocacy groups, the United States Congress passed the Intermodal Surface Transportation Efficiency Act (ISTEA). This forced states and metropolitan planning organizations to incorporate bicycling and walking into their transportation plans and also dedicated federal funding for “enhancements” or alternative transportation projects, i.e. bicycling facilities. While ISTEA created the Enhancement Program for these bicycle projects, some states and MPOs at the time simply mentioned bicycling and walking in their transportation plans and did not seek federal funding for new bicycling infrastructure projects. The Enhancement Program programmed roughly $972 million for bicycle projects, which was much higher than the $41 million of federal funds which had been spent on bicycle facilities over the previous 20 years. Of this new $972 million, 13% was used for on-road bicycle facilities and 86% was used for the construction of off-highway paths and trails. Following the success of ISTEA in regards to bicycling facilities, the US Congress increased funding levels for bicycling facilities by 50% and incorporated educational and safety activities for bicyclists as projects eligible for funding in the 1998 act, Transportation Equity Act for the Twenty-First Century (TEA-21).

Following TEA-21, a new transportation bill titled the Safe, Accountable, Flexible, Efficient, Transportation Equity Act (SAFETEA-LU) was passed in 2006. This bill authorized greater amounts of funding for bicycling infrastructure improvements and also included stimulus funding which was applied during the recession. Under SAFETEA-LU the annual funding level for walking and cycling rose to nearly $1 billion per year. Considering that the previous funding levels under TEA-21 were just $360 million annually, it is clear that the federal government intended to encourage walking and cycling through making more funding available to these kinds of infrastructure projects. Although these funds were available for projects other than just dedicated bikeway facilities, many of the dedicated bikeways constructed during the time of SAFETEA-LU utilized the available federal funding sources. As SAFETEA-LU was set to expire in 2009, the federal government continued to extend this bill until 2012 when a new transportation bill was finally passed; just under three years overdue. Moving Ahead for Progress in the 21st Century (MAP-21) reversed the upward trend in funding levels for walking and cycling projects which had been carried forward through SAFETEA-LU and instead significantly cut available funding levels. The funding available for walking and bicycling projects in 2013 was reduced to $808 million compared to the $1.2 billion available for the same projects in 2011. This reduction in available funding has not significantly curbed the rate of construction of dedicated bikeway facilities across the United States but due to the long time frame which the planning for these projects generally entails, this reduction in funding could have delayed effects yet to be seen in the coming few years. Additionally, MAP-21 was originally set to expire in late 2014 but has since been extended through May 2015, at which time a new transportation funding bill is intended to be passed. However, due to the congressional gridlock and a historically low number of bills being passed in the previous two congresses (112th and 113th Congresses) there is no guarantee that a new bill will be put in place by May. Thanks to this lack of certainty in regards to transportation funding in the future, there may be a back log of dedicated bikeway projects waiting to submit for approval of funding. This could artificially retard the rate of construction of dedicated bikeway facilities in the coming years until federal funding another federal transportation bill, not a temporary extension, is passed.

The Growth of the Mode

In the American context, growth in the mileage of dedicated bikeway facilities was rather stagnant until the late 2000’s when construction of these facilities began to increase rapidly. During the 1970’s there were a handful of facilities constructed primarily in Champaign-Urbana and a few locations in California but the 1980’s saw a total of 5.67 miles constructed. Only four facilities were constructed in the 1980’s and were located across the country from Oregon to Texas. Following this, the 1990’s saw more new mileage of dedicated bikeway construction (11.18) but just three total new facilities.

This slow level of growth in the construction of dedicated bikeway facilities can be attributed to the meager level of funding available for this kind of infrastructure investment. Even though more funding for this kind of facility was made available as early as 1991 in the ISTEA bill, it took nearly a decade before a noticeable rise in dedicated bikeway facility construction occurred. Another reason for this could be the fact that cities were applying available funds to lower cost facilities such as bike lanes before dedicating more time and funding towards more intensive dedicated bikeway projects but this is outside of the scope of this paper.

Real noticeable growth truly began in 2008 when a total of 4.49 miles were constructed across the country, followed by a total of 8.41 miles being constructed in 2009. The five years have continued to see large increases in the cumulative number of dedicated bikeway miles across the country. The most prolific year to date of dedicated bikeway construction was 2012 in which 38.04 new miles of dedicated bikeways were constructed. Within the past seven years, the number of dedicated bikeway miles in the United States has grown by nearly five times, increasing from 34.6 in 2007 to 151.43 as of November, 2014. Additionally, a total of nearly 67 miles of additional dedicated bikeway are planned to be constructed by 2017 in the United States.

Quantitative Analysis

Data for this analysis was taken from an online inventory of dedicated bikeways hosted by peopleforbikes.org. While this dataset includes the distance, location, and physical characteristics of the individual dedicated bikeways, there is a possibility that the dataset is not completely exhaustive. This dataset goes begins in 1874 and includes planned facilities all the way through 2019. However, because the construction of dedicate bikeways has nearly an 80 year gap between the two bikeways built in the 1800’s (1874 & 1894) and the construction of a bikeway in 1970, the data analysis used data from 1970 through the present in order to prevent the model being skewed by these outliers.

The dataset can be broken into two very distinct phases, the birth phase (1970-2006) and the growth phase (2006-present). These two phases are marked by wildly different growth rates and the passing of SAFETEA-LU in 2006, which significantly increased the funding available for bicycling infrastructure projects. This bill served as the catalyst which launched the growth phase of the dedicated bikeways in the United States.

Graph of two models designed to describe the birth and growth phases of dedicated bikeways in the United States.

In the graph above, it is easy to see the distinctly different phases in the lifecycle of US dedicated bikeways. Growth before 2006 was very slow and only increased by 26 miles over this 36 year period. This is in direct contrast to the growth phase which has seen roughly 117 miles of dedicated bikeways being constructed in just a seven year period. In order to model these two distinct phases, the data was broken into the two respective time periods and analyzed separately using a logistic regression model, otherwise known as the Ordinary Least Squares model. In this model S(t) = K/[1+exp(-b(t-t0)]

Where:

S(t) is the status measure (number of total miles)

t is time (annual, 1970-2006;2006-2014)

t0 is the inflection time (half of the peak)

K is saturation status level (the peak)

b is a coefficient, which measures the amount of impact on the independent variable.

Due to the small number of existing miles of dedicated bikeways, metrics from the Netherlands was used to estimate the K value. The reason for using the Netherlands as a rubric for success in terms of dedicated bikeways in the American sense is that the system in the Netherlands is largely built out and is hailed as one of the most expansive in the world. The Netherlands currently has roughly 21,000 miles of dedicated bikeways and 86,000 miles of public paved roads, which makes a ratio of dedicated bikeways to paved roads of 1:4. Applying this ratio to US paved road mileage, roughly 2,646,000 miles, results in a K level of 661,000 miles of dedicated bikeways.

Graph showing the birth & growth models used compared to the initial singular model, which was not used.

Using this K value, two distinct models were created which modeled the birth phase and the growth phase. The birth phase model, which analyzed the data from 1970 to 2006, had an intercept of -102.3918, a slope of .046235073, and resulted in an R square value of .9182. The growth model, which analyzed data from 2006 through November 2014, had an intercept of -403.522, a slope of .19619, and resulted in an R squared value of .9318. Both these models resulted in a much more accurate model for each phase than the initial model developed, which did not differentiate between phases and had an R squared value of .89551, an intercept of -117.52, and a slope of .053862. This model greatly over-estimated many values for between 1990 and 2010 and severely under-estimated the values after 2010. This is shown in the graph to the second graph to the right.

Upon receiving more data, it is likely that two models will not be necessary for this transportation modes lifecycle. However, because the currently available dataset contains data with such divergent trends it became necessary to develop two models in order to attain the best fit.