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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-HRT-05-138
Date: July 2006

Shared-Use Path Level of Service Calculator

A User's Guide

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During the last 20 years, there has been an explosion in shared-use path construction across the United States and Canada. These new paths take many forms–rail-trails, greenway trails through linear parks, waterfront paths along beaches and oceans, and side-paths along road corridors. [1] These paths serve a wide variety of nonmotorized travelers–bicyclists, skaters, scooters, runners, walkers, people with disabilities, people pushing strollers, children, the elderly, and others. Many of these paths have become extremely popular and well used, especially in urban and suburban communities. Some shared-use paths are popular to the point of suffering from their success, i.e., periodic crowding and user conflicts begin to affect user enjoyment and safety.

In general, there are a variety of reasons why trail use is on the rise. Trail activities remain high on the list of most popular outdoor recreation activities, and U.S. participation levels in trail activities continue to trend upwards. [2] For example, between 1994 and 2000, participation in the following trail activities increased considerably: walking (35 percent increase); running (43 percent increase); bicycling (50 percent increase); and day hiking (52 percent increase).(1) As more trails are built in urban and suburban communities, they increase the population's access to close-to-home recreation and enable people to participate in trail use more often. Trail users and equipment continue to diversify, encouraging new constituencies. Finally, the purposes for trail use are expanding, as urban and suburban trails are used for utilitarian and commuting transportation, as well as for recreation.

In many communities, shared-use paths are an integral part of the multimodal transportation system. As transportation planners and decisionmakers have focused increased attention on trail development, concern about trail safety and the management of high user volumes has risen as well. However, trail and nonmotorized transportation planners have had few tools and little data to guide them in managing higher volumes and the increasingly diverse trail user modes. It remains unclear as to how many users are too many for any given trail width, or how user flow can be optimized using trail design or operational techniques. Research is needed to provide trail planners, designers, and managers with additional tools that can be used to make the best trails possible.



This guide is intended primarily for trail planners, designers, and managers, which include professionals from a wide variety of disciplines–planners, landscape architects, transportation engineers, bicycle and pedestrian transportation specialists, and park and recreation planners and managers. It may also be useful for trail, bicycle, and pedestrian advocates; elected officials; planning and park commissioners; and other members of the public–especially those who find themselves involved in trail planning efforts or in situations involving trail user conflicts that stem from high volumes and diverse mode mixes. These conditions are increasingly common on trails located in urban, suburban, and high-use recreational areas.

The purpose of this guide is to introduce practitioners and others to: 1) the findings of our study on the quality of service on trails; 2) a new analytical tool called the Shared-Use Path Level of Service (LOS) Calculator, and 3) potential implications for trail design. The tool can be used for a variety of trail planning tasks, where quantitative evaluation is needed to assist in solving design or management problems, as for example:

  • To plan appropriate widths and cross sections for new trails.
  • To evaluate LOS provided on existing trails.
  • To guide the design of improvements for existing trails, where additional capacity is needed.
  • To determine how many additional users a trail may be able to serve, given a minimum LOS threshold.
  • To evaluate LOS for specific timeframes, when particular trip purposes need to be served, such as weekday morning and evening periods, when commuting trips are heaviest.
  • To determine LOS at a particular location on a trail, such as a narrow pinch point in an unusually high use area or in an area with many reported user conflicts.

Other important findings of this research include the development of baseline data to which trail data from all parts of the country and from many different settings can be compared, including:

  • Average user speeds for five major trail user groups.
  • Documentation of diverse user volume ranges.
  • Documentation of diverse ranges of user mix.
  • Development of an average trail volume and mode split profile.

Readers of this guide may understand the term shared-use path (or multiuse trail) to be applicable to a very wide range of facility types and settings. It is important to note that the analytical tool introduced in this guide and the research behind it were not developed to apply to every type of shared-use path. The list below describes the limits of the study and the applicability of its findings.



  • The tool presented in this guide is applicable only to paved hard-surface paths (asphalt or concrete). Paths surfaced with gravel, dirt, wood chips, or other materials were not evaluated in the research, and surface type and quality are not a component of this LOS evaluation.

  • The tool evaluates path LOS for bicycle mobility. While the findings and recommendations will likely improve a trail's conditions for all users (pedestrians, runners, in-line skaters, etc.), the study was conducted from the point of view of the bicyclist.

  • The tool does not accommodate use of specific mode split inputs for users outside the five user groups identified in this research–i.e., adult bicyclists, pedestrians, runners, in-line skaters, and child bicyclists. Moreover, it is not applicable to evaluating the unique impacts on LOS that other trail users may have, such as push scooters, wheelchair users, equestrians, cross-country skiers, electric vehicles, or others who may be a part of the mix on some trails.

  • This tool is not applicable to trail segments with stop signs, signal controls, or road crossings placed more frequently than every 0.40 kilometers (km) (0.25 miles (mi)).

  • The tool is structured to address two-way, shared-use path facilities. It was not created with bicycle-only or one-way paths in mind; however, it may be applicable to paths of this nature. It does not apply to on-street bicycle facilities.



This guide is divided into six chapters following this introduction.

Chapter 2 summarizes the purpose and objectives of the research, its approach, and its basic findings. It provides definitions for key terms used in the guide and a list of various factors studied during data analysis. Findings include a summary of characteristics found on the study trails, user perception survey results, and the development of a data profile for an average trail. Appendix A provides a full data profile for the 15 study trails.

Chapter 3 provides an introduction to the concept of LOS and describes how it has been applied to shared-use paths. It provides a brief description of the mathematical model used to create the Shared-Use Path LOS Calculator and describes how trail LOS grades should be interpreted. It concludes with a table of LOS scores and grades for the 15 trails examined in this study.

Chapter 4 describes how to apply the Shared-Use Path LOS Calculator to various trail planning and design issues. Data requirements are discussed, as well as model assumptions and default values. This chapter concludes with an introduction to the quick reference, "Look-Up Tables," where a range of typical trail widths, volumes, and mode mixes are listed, with corresponding LOS scores and grades. The look-up tables are provided in appendix C.

Chapter 5 provides a step-by-step guide to using the Shared-Use Path LOS Calculator.

Chapter 6 discusses possible implications of research on trail design. Topics discussed include trail width, striping options, and use of separate treadways for select user types. Trail operation and management decisions may also be informed by analysis conducted with this tool.

Chapter 7 includes two fictional case studies that describe diverse applications of the calculator to real-life situations: first, to evaluate the performance of an existing trail to determine how much trail widening may be needed, and second, to determine the appropriate width when planning the cross section of a new trail.



This Federal Highway Administration (FHWA) publication, FHWA-HRT-05-138, Shared-Use Path LOS Calculator–A User's Guide, and the associated Shared-Use Path Level of Service Calculator are two of the products resulting from this research project. Other products include FHWA-HRT-05-137, Evaluation of Safety, Design, and Operation of Shared-Use Paths–Final Report and an accompanying TechBrief.



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