Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296

July 2006

Calculator

A USER’S GUIDE

 Shared-Use Path Level of Service
FOREWORD 

Shared-use paths are paved, off-road facilities designed for travel by a variety of nonmotorized users, including 

bicyclists, pedestrians, skaters, runners, and others. Shared-use path planners and designers face a serious challenge 

in determining how wide paths should be and whether the various modes of travel should be separated from each 

other. Currently, very little substantive guidance is available to aid in those decisions. 

This document describes how to use a new method to analyze the quality of service provided by shared-use paths of 

various widths that accommodate various travel mode splits. Given a count or an estimate of the overall path user 

volume in the design hour, the new method described here can provide the level of service (LOS) for path widths 

ranging from 2.4 to 6.1 meters (8.0 to 20.0 feet). The document describes in detail the input data needed to begin 

using the method, provides step-by-step instructions, and provides example applications of the new method. This 

document also describes how to use a spreadsheet calculation tool called SUPLOS that was also developed as part of 

the same effort and that is being circulated by the Federal Highway Administration. 

The information in this document should be of interest to planners, engineers, park and recreation professionals, and 

others involved in the planning, design, operation, and/or maintenance of shared-use paths. In addition, this 

document will be of interest to researchers investigating how to analyze multiple modes of travelers in a finite space 

with minimal traffic control. 

 Michael F. Trentacoste 

 Director, Office of Safety 

 Research and Development 

Notice 

This document is disseminated under the sponsorship of the Department of Transportation in the interest of 

information exchange. The U.S. Government assumes no liability for the use of the information contained in this 

document. This report does not constitute a standard, specification, or regulation. 

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in 

this report only because they are considered essential to the objective of the document. 

Quality Assurance Statement 

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, 

and the public in a manner that promotes public understanding. Standards and policies are used to ensure and 

maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues 

and adjusts its programs and processes to ensure continuous quality improvement. 
1. Report No. 

 FHWA-HRT-05-138 

2. Government Accession No. 3. Recipient’s Catalog No. 

5. Report Date 

July 2006 

4. Title and Subtitle 

 Shared-Use Path Level of Service Calculator—A User’s Guide 

6. Performing Organization Code 

7. Author(s) 

R.S. Patten, R.J. Schneider, J.L. Toole, J.E. Hummer and N.M. Rouphail 

8. Performing Organization Report No. 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

North Carolina State University 

Department of Civil, Construction, and Environmental Engineering 

 Raleigh, NC 27695-7908 11. Contract or Grant No. 

DTFH61-00-R-00070 

13. Type of Report and Period Covered 

User’s Guide

12. Sponsoring Agency Name and Address 

Office of Safety Research and Development 

Federal Highway Administration 

 6300 Georgetown Pike 

McLean, VA 22101 September 2000 – May 2005 

14. Sponsoring Agency Code 

15. Supplementary Notes: 

Contracting Officer’s Technical Representative (COTR): Ann Do, HRDS-06 

16. Abstract 

17. 

Shared-use paths are becoming increasingly busy in many places in the United States. Path designers and operators need 

guidance on how wide to make new or rebuilt paths and whether to separate the different types of users. The current guidance is

not very specific, has not been calibrated to conditions in the United States, and does not accommodate the range of modes found 

on a typical U.S. path. The purpose of this project was to develop a level of service (LOS) estimation method for shared-use 

paths that overcomes these limitations. The research included the development of the theory of traffic flow on a path, an 

extensive effort to collect data on path operations, and a survey during which path users expressed their degree of satisfaction 

with the paths shown on a series of videos. 

Based on the theory developed and the data collected, the researchers developed an LOS estimation method for bicyclists that 

requires minimal input and produces a simple and useful result. The method requires only four inputs from the user: One-way 

user volume in the design hour, mode split percentages, trail width, and presence or absence of a centerline. Factors involved in 

the estimation of an LOS for a path include the number of times a typical bicyclist meets or passes another path user and the 

number of those passes that are delayed. The method considers five types of path users when calculating adult bicyclists’ LOS, 

including other adult bicyclists, child bicyclists, pedestrians, runners, and in-line skaters. 

This report provides step-by-step instructions on how to use the LOS procedure and spreadsheet calculation tool, which can be 

downloaded from the Turner-Fairbank Highway Research Center Web site at www.tfhrc.org. Other products of the effort include 

FHWA-HRT-05-137 Evaluation of Safety, Design, and Operation of Shared-Use Paths: Final Report, which documents the 

research and the spreadsheet calculation tool and is the basis of FHWA-HRT-05-139 Evaluation of Safety, Design, and 

Operation of Shared-Use Paths TechBrief. 

17. Key Words 

Path, trail, bicycle, shared-use, LOS, width, 

pedestrian, in-line skater 

18. Distribution Statement 

No restrictions. This document is available to the public through 

the National Technical Information Service, Springfield, VA 

22161, telephone (703) 487-4650. 

19. Security Classif. (of this report) 

Unclassified 

20. Security Classif. (of this page) 

Unclassified 

21. No. of Pages 

67 

22. Price 

 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized 
ii 

SI* (MODERN METRIC) CONVERSION FACTORS 

APPROXIMATE CONVERSIONS TO SI UNITS

Symbol When You Know Multiply By To Find Symbol 

LENGTH 

in inches 25.4 millimeters mm 

ft feet 0.305 meters m 

yd yards 0.914 meters m 

mi miles 1.61 kilometers km 

AREA 

in2 square inches 645.2 square millimeters mm2

ft2 square feet 0.093 square meters m2

yd2 square yard 0.836 square meters m2

ac acres 0.405 hectares ha

mi2 square miles 2.59 square kilometers km2

VOLUME 

fl oz fluid ounces 29.57 milliliters mL 

gal gallons 3.785 liters L 

ft3 cubic feet 0.028 cubic meters m3 

yd3 cubic yards 0.765 cubic meters m3 

NOTE: volumes greater than 1000 L shall be shown in m3

MASS 

oz ounces 28.35 grams g

lb pounds 0.454 kilograms kg

T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t") 

TEMPERATURE (exact degrees) o

F Fahrenheit 5 (F-32)/9 Celsius oC 

or (F-32)/1.8 

ILLUMINATION 

fc foot-candles 10.76 lux lx

fl foot-Lamberts 3.426 candela/m2 cd/m2

FORCE and PRESSURE or STRESS 

lbf poundforce 4.45 newtons N 

lbf/in2 poundforce per square inch 6.89 kilopascals kPa 

APPROXIMATE CONVERSIONS FROM SI UNITS 

Symbol When You Know Multiply By To Find Symbol 

LENGTH

mm millimeters 0.039 inches in 

m meters 3.28 feet ft 

m meters 1.09 yards yd 

km kilometers 0.621 miles mi 

AREA mm2

 square millimeters 0.0016 square inches in2 

m2 square meters 10.764 square feet ft2 

m2 square meters 1.195 square yards yd2 

ha hectares 2.47 acres ac

km2 square kilometers 0.386 square miles mi2 

VOLUME 

mL milliliters 0.034 fluid ounces fl oz 

L liters 0.264 gallons gal 

m3 cubic meters 35.314 cubic feet ft3 

m3 cubic meters 1.307 cubic yards yd3 

MASS 

g grams 0.035 ounces oz

kg kilograms 2.202 pounds lb

Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T 

TEMPERATURE (exact degrees) o

C Celsius 1.8C+32 Fahrenheit oF 

ILLUMINATION 

lx lux 0.0929 foot-candles fc 

cd/m2 candela/m2 0.2919 foot-Lamberts fl

FORCE and PRESSURE or STRESS 

N newtons 0.225 poundforce lbf 

kPa kilopascals 0.145 poundforce per square inch lbf/in2

*SI is the symbol for th International System of Units. Approp e riate rounding should be made to comply with Section 4 of ASTM E380. 

(Revised March 2003)
iii 

TABLE OF CONTENTS 

1. Introduction................................................................................................................... 1 

How To Use This Guide......................................................................................... 1 

For What Types Of Shared-Use Paths Is This Study Applicable?......................... 2 

Chapter Summaries ................................................................................................ 3 

Other Reports and Products Generated by This Study........................................... 3 

2. An Overview of the Research....................................................................................... 5 

Problem Statement.................................................................................................. 5 

Purpose ................................................................................................................... 6 

Approach ................................................................................................................ 6 

Findings.................................................................................................................. 7 

3. LOS for Shared-Use Paths.......................................................................................... 13 

What Is LOS? ....................................................................................................... 13 

The Shared-Use Path LOS Model........................................................................ 13 

Interpreting Shared-Use Path LOS Grades........................................................... 14 

LOS Scores for 15 Study Trails............................................................................ 15 

4. Applying the Model to Your Trail.............................................................................. 17 

Link Analysis........................................................................................................ 17 

Data Requirements............................................................................................... 18 

Assumptions and Defaults.................................................................................... 21 

Shared-Use Path LOS Look-Up Tables ............................................................... 22 

5. Instructions For Using the Shared-Use Path LOS Calculator..................................... 25 

Introduction .......................................................................................................... 25 

Step-by-Step Instructions..................................................................................... 25 

6. Implications of this Research forTrail Design............................................................ 27 

Trail Width ........................................................................................................... 27 

Centerline Striping................................................................................................ 27 

Multilane Striping................................................................................................. 28 

Multiple Treadways.............................................................................................. 28 

Trail Operations and Management ....................................................................... 28 

7. Example Applications: Fictional Case Studies........................................................... 29 

Case Study 1: Testing Design Options for the Stone Creek Trail Upgrade ......... 29 

Case Study 2: Testing Design Options For The De Soto River 

Waterfront Trail ............................................................................................. 33 

Appendix A. Study Trail Profiles ................................................................................... 39 

Appendix B. Factors Used in the LOS Model................................................................ 55 

Appendix C. LOS Look-Up Tables ................................................................................ 57 

References........................................................................................................................ 63 
iv 

LIST OF FIGURES 

Figure 1. Equation. Basic SUPLOS model. ...................................................................................14 

Figure 2. Screen capture. Existing conditions LOS analysis. ........................................................31 

Figure 3. Screen capture. LOS for selected design widths. ...........................................................32 

Figure 4. Screen capture. LOS for 10-year projected volumes and 

selected design widths....................................................................................................37 

LIST OF TABLES 

Table 1. Variations in trail user volume.............................................................................. 8 

Table 2. Variations in trail user mix (mode split)............................................................... 9 

Table 3. Data profile for the average trail........................................................................... 9 

Table 4. Average speed by mode...................................................................................... 10 

Table 5. SUPLOS scale..................................................................................................... 14 

Table 6. Interpreting SUPLOS grades. ............................................................................. 15 

Table 7. Study trail level of service grades and characteristics. ....................................... 17 

Table 8. Correlation of trail widths and operational lanes................................................ 22 

Table 9. Selected cross sections........................................................................................ 33 

Table 10. Volume and mode split estimates to test in the calculator................................ 35 

Table 11. Factors used in the shared-use path LOS model............................................... 55 

Table 12. Shared-use path level of service look-up table, typical mode split. ................. 57 

Table 13. Shared-use path level of service look-up table, high bicycle mode split.......... 58 

Table 14. Shared-use path level of service look-up table, high pedestrian mode split..... 59 

Table 15. Shared-use path service volume look-up table, typical mode split................... 60 

Table 16. Shared-use path service volume look-up table, high bicycle mode split.......... 61 

Table 17. Shared-use path service volume look-up table, high pedestrian mode split..... 62 
1 

1. INTRODUCTION 

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.*

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. †

 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. 

HOW TO USE THIS GUIDE 

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 

 

*

 Throughout this document, the terms shared-use path, path, pathway, and trail will be used interchangeably. They 

should be understood to mean a hard-surface treadway that is open to a variety of nonmotorized users, including 

bicyclists, pedestrians, runners, and skaters, and serves both transportation and recreational purposes. 

†

 Walking, bicycling, running or jogging, and day hiking rank 1st, 9th, 11th, and 12th, respectively, out of 35 outdoor 

recreation activities surveyed. Outdoor Recreation in American Life: National Assessment of Demand and Supply 

Trends, Ken Cordell, Sagamore Publishing, 1999.
2 

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. 

FOR WHAT TYPES OF SHARED-USE PATHS IS THIS STUDY APPLICABLE? 

• 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, inline 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)). 
3 

• 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. 

CHAPTER SUMMARIES 

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. 

OTHER REPORTS AND PRODUCTS GENERATED BY THIS STUDY 

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. 

5

2. AN OVERVIEW OF THE RESEARCH 

PROBLEM STATEMENT 

During the design of every shared-use path, someone eventually asks, “How wide should this 

pathway be?” That question nearly always raises even more questions: “What types of users can 

we reasonably expect? When will we need to widen the path? Do we need to separate different 

types of users from each other?” 

At the present time, conventional design manuals provide little guidance on these issues. The 

1999 American Association of State Highway and Transportation Officials (AASHTO) Guide for 

the Development of Bicycle Facilities states, “Under most conditions, a recommended paved 

width for a two-directional shared-use path is 3.0 m (10.0 feet).... Under certain conditions it may 

be necessary or desirable to increase the width of a shared-use path to 3.6 m (12.0 feet) or even 

4.2 m (14.0 feet), due to substantial use by bicycles, joggers, skaters and pedestrians.”(2) No 

further guidance is given to determine what specific levels of use—or mixture of uses—warrants 

a wider pathway or a separation of users. The purpose of this research is to fill this information 

gap and to give planners, designers, and managers the necessary tools to make more informed 

decisions regarding trail width and design. 

Previous research efforts have laid the groundwork for the study of this problem. In order to 

provide some level of guidance in the year 2000 edition of the FHWA Highway Capacity Manual

(HCM)(3), Rouphail, et al., recommended an analytical procedure to determine LOS for bicyclists 

on shared off-street paths.(4) Rouphail, et al., adapted a procedure originally developed by Hein 

Botma(5) in the Netherlands.(4,5)

Botma is considered an important pioneer in the development of early measures of user density 

(crowding), flow characteristics, and hindrance for bicyclists using shared-use paths. His 

procedure bases LOS on two factors: first, the number of trail users passed in the opposing 

direction (meetings), and second, the number of slower trail users that are traveling in the same 

direction that a bicyclist must overtake (active passes). A useful starting point, Botma’s 

framework had a variety of limitations for application in the United States.(5) 

The Botma method addressed only two trail user modes—bicycles and pedestrians. Runners, inline skaters, and other common path users were not incorporated. The significant presence of 

these path users on U.S. trails suggested that a tool developed for application in the United States 

should attempt to address them. 

Next, the LOS scores generated by the Botma method were developed based on his experience of 

shared-use paths in the Netherlands and were not calibrated to the opinions of actual trail users.(5)

Harkey, et al., (1998) and Landis, et al., (1997) have developed LOS criteria for on-street 

bicycling conditions, which are validated against user perceptions of the quality of service.(6,7)

The success of their work has shown that when quantitative measures are statistically calibrated 

with user perceptions, the resulting model has greater acceptance with stakeholders at all levels—

technical staff, elected officials, facility users, and the general public.

Finally, Botma’s work did not include investigation of any other factors to determine if they 

might have a significant influence on trail users’ perceived LOS.(5) Factors such as delay, trailstriping patterns, the presence of usable shoulders, sight distance, or lateral clearance all might be 

important. Identification, analysis, and incorporation of other criteria that may contribute to actual 

users’ opinion of LOS will ensure the development of a more effective predictive tool. 
6

PURPOSE 

The purpose of this study was to gather and analyze background data necessary to develop a 

model that professionals can use to evaluate the operational effectiveness of a shared-use path, 

create and test that model, and develop a user-friendly interface and guide for its use. 

APPROACH 

To accomplish this purpose, a three-step approach was developed: 

1. Review prior research and develop a sound theoretical approach to solving the problem. 

2. Gather the necessary operational and user perception data. 

3. Analyze the data and develop and test a model that can be used by practitioners as a 

planning and design tool. 

Step 1: Develop Theoretical Approach 

Step one was accomplished through the completion of a literature review and the development of 

a technical dissertation that described the theoretical approach. The results of these interim 

products are summarized separately from this User’s Guide, in the project’s Final Report.(8) 

Step 2: Data Collection 

Step two involved gathering and analyzing two types of data, operational data and user 

perceptions. Operational data collection involved gathering volume, speed, and mode split data 

from test locations along 15 trails throughout the United States. It also included gathering 

sufficient information about the characteristics of each study trail to create a thorough path profile 

and also testing other factors that might prove influential to bicyclists’ LOS. These data included 

path width, surface type, path setting, sight distance, lateral clearance, presence of a shoulder or 

adjacent unpaved treadway, and other factors. See appendix A for profiles of the 15 study trails. 

User perception data were gathered by surveying over 100 typical trail users regarding their 

perceptions of four aspects of shared-use path operations: 

• Lateral spacing. 

• Longitudinal spacing. 

• Ability to pass. 

• Overall perception of comfort and freedom to maneuver. 

Designing this aspect of the research posed a challenge: how to have a group of approximately 

100 survey participants experience a wide variety of trail conditions. Because cost and logistics 

made the physical movement of groups of respondents to multiple trail survey sites impossible, it 

was decided to bring the study trail sites to the survey participants through the use of videotaped 

trail experiences. 

A total of 105 survey participants were gathered in two metropolitan areas—Raleigh-DurhamChapel Hill, NC, and Washington, DC. Each group of participants viewed 36 one-minute video 

clips of a test bicyclist traveling along a section of one of the study trails.*

 By viewing exactly the 

same video clips, two geographically distinct survey groups vicariously experienced the same 

variety of trails and trail conditions. 

 

*

 Five of the 15 study trails were not represented in the video clips used for the user perception survey: the W&OD, 

Grant’s, Capital Crescent, Pinellas, and White Creek trails. 
7

The video clips were created using a helmet-mounted video camera. A member of the research 

team (the test bicyclist) bicycled down a 0.8-km (0.5-mi) segment of each of the study trails while 

the camera taped the view of the trail ahead. Approximately 60 three-minute video clips were 

created for each of the study trails.†

 The 36 one-minute video clips used for the survey were 

selected from this footage. 

Survey participants viewing the video clips could see the path ahead, the landscape on each side 

of the trail, the oncoming trail traffic, and slower moving traffic in the test bicyclist’s lane. At 

times, the video clips included a tape of passing maneuvers, when the test bicyclist overtook 

slower moving traffic. The test bicyclist tried to remain at a constant speed for the duration of 

each video clip. 

The participants in the survey were asked to score each video clip for the four aspects noted 

previously: lateral spacing, longitudinal spacing, ability to pass, and overall perception of comfort 

and freedom to maneuver. 

Step 3: Data Analysis/Development of the Model 

The raw operational data were analyzed for three purposes: to develop volume and mode split 

profiles for each study trail; to develop a variety of constants and other factors for use in the LOS 

model; and to validate the theoretical methods developed to predict meetings and passings. The 

constants gathered included average and standard deviation speeds for all trail-user types, a peakhour factor, a propensity-to-pass factor, and passing-distance intervals. 

The user perception survey results were expected to correlate with measurable events on each 

trail. Each trail was analyzed for the following four measurable events: 

• Meetings: the number of trail users (by user type) that passed the test bicyclists going in 

the opposite direction. 

• Active passes: the number of users traveling in the same direction (by user type) that 

were passed by the test bicyclists. 

• Passive passes: the number of times the test bicyclist was passed by trail users traveling 

in the same direction. 

• Delayed passes: the number of times that the test bicyclist needed to pass in order to 

maintain speed but was blocked by other users traveling in either direction. 

A full discussion of model development and creation of the Shared-Use Path LOS Calculator is 

presented in chapter 3. 

FINDINGS 

The most important findings of this study can be organized into two groups: characteristics of 

study trails and perception survey results. 

Characteristics of Study Trails 

Typical 2-way trail user volumes were found to vary considerably from as low as 43 per hour on 

the W&OD Trail in Northern Virginia to 2,316 per hour on the North Beach Lakefront Path in 

 

†

 Weather and technical problems prevented a full set of 60 three-minute clips from being created for four of the study 

trails. See tables 1–4 for the number of valid data collection trials that were completed for each study trail. 
8

Chicago, IL. ‡

 Per-hour volume data were created by averaging the counts from approximately 60 

three-minute trials taken over the course of a peak usage day (from about 10 a.m. to 5 p.m.), 

typically Saturday or Sunday. Where commuter traffic was significant, some data were collected 

on weekday mornings. See table 1 for a summary of average per-hour volumes by study trail. 

Table 1. Variations in trail user volume. 

Path name Location 

Average 

two-way 

volume 

(per hour) 

Trail 

width 

(ft) 

Successful 

data collection 

trials 

(3 minutes each) 

W&OD Trail Arlington, VA 44 10.0 4 

Honeymoon Island Trail Dunedin, FL 110 12.0 48 

Pinellas Trail Pinellas County, FL 120 15.0 57 

Grant's Trail St. Louis County, MO 122 12.0 30 

Capital Crescent Trail Washington, DC 159 10.0 9 

Lake Johnson Trail Raleigh, NC 205 8.0 58 

White Creek Trail Dallas, TX 216 8.0 60 

White Rock Lake Trail Dallas, TX 252 14.0 60 

Forest Park Trail St. Louis, MO 299 10.0 57 

Sammamish River Trail Redmond, WA 418 10.0 58 

Charles River Bike Path Boston, MA 438 8.0 60 

Minuteman Bikeway Arlington, MA 442 12.0 60 

South Bay Trail Santa Monica, CA 616 14.0 60 

Mill Valley— 

Sausalito Pathway Marin County, CA 641 9.5 60 

Lakefront Trail Chicago, IL 2320 20.0 90 

1 ft = 0.30 m 

User mix also varied considerably on the 15 study trails. Users on five trails were observed to 

comprise more than 70 percent adult bicyclists. On six trails, more than 35 percent of users 

traveled on foot (pedestrians and runners). Observation of user types found few users outside of 

the five basic user groups presented in table 2. Wheelchair users and push scooters were observed 

on some trails, but not in sufficient quantity to develop a statistically valid average speed profile. 

 

‡

 Due to adverse weather conditions, very few data collection trials could be executed on the W&OD and Capital 

Crescent trails in the Washington, DC, metropolitan area. 
9

Table 2. Variations in trail user mix (mode split). 

Average percent of volume by trail user type 

(mode split)

Path name Location 

Trail 

width 

(ft) 

Adult 

bicyclists 

Pedestrians Runners Skaters Child 

bicyclists 

Pinellas Trail Pinellas County, FL 15.0 81.4 4.6 2.3 11.6 0.0 

Sammamish 

River Trail Redmond, WA 10.0 78.9 3.4 3.4 6.0 8.4 

W&OD Trail Arlington, VA 10.0 73.7 5.3 15.8 5.3 0.0 

Charles River 

Bike Path Boston, MA 8.0 72.3 8.2 3.8 14.7 1.1 

White Rock 

Lake Trail Dallas, TX 14.0 71.6 13.6 8.0 3.4 3.4 

White Creek 

Trail Dallas, TX 8.0 64.8 9.9 6.6 14.3 4.4 

Mill Valley—

Sausalito 

Pathway Marin County, CA 9.5 62.8 7.8 27.8 0.0 1.7 

Grant's Trail St. Louis County, MO 12.0 59.2 16.3 4.1 10.2 10.2 

Capital Crescent 

Trail Washington, DC 10.0 55.9 17.0 18.6 3.4 5.1 

Minuteman 

Bikeway Arlington, MA 12.0 51.9 6.2 15.6 18.1 8.1 

Lakefront Trail Chicago, IL 20.0 48.8 20.5 17.7 12.3 0.7 

South Bay Trail Santa Monica, CA 14.0 40.3 17.4 12.5 25.0 4.9 

Forest Park 

Trail St. Louis, MO 10.0 33.0 24.4 27.8 13.9 0.9 

Honeymoon 

Island Trail Dunedin, FL 12.0 22.9 54.2 12.5 8.3 2.1 

Lake Johnson 

Trail Raleigh, NC 8.0 14.1 63.3 21.9 0.0 0.8 

1 ft = 0.30 m 

Based on the width, centerline, volume, and mode split data collected on the study trails, an 

average trail profile was developed. To ensure that the outliers in the data set did not skew the 

average, the high- and low-volume trails (Lakefront and W&OD, respectively) were not used to 

calculate the data profile for the average trail in table 3. Mode split shares were rounded to the 

nearest five. 

Table 3. Data profile for the average trail. 

Width Centerline 

One-way 

volume 

per hour 

Adult 

bicycles Pedestrians Runners Skaters Child 

bicycles 

Average 

trail 11 ft Yes 105 55% 20% 10% 10% 5% 

1 ft = 0.30 m 

This research also yielded a large volume of data on average speeds for different types of trail 

users. Table 4 shows the average user speed for each mode and the typical range of variation 

(standard deviation). 
10

Table 4. Average speed by mode. 

Trail user type (mode) Average speed (mi/h) Standard deviation (mi/h) 

Adult bicyclists 12.8 3.4 

In-line skaters 10.1 2.7 

Child bicyclists 7.9 1.9 

Runners 6.5 1.2 

Pedestrians 3.4 0.6 

1 mi/h = 1.6 km/h 

Perception Survey Results 

As explained above, a survey of 105 trail users (primarily bicyclists) was used to determine what 

factors bicyclists found to be significant in their evaluation of comfort and freedom to maneuver 

on shared-use paths. Using standard statistical methods, a wide variety of factors were tested to 

determine their overall influence on survey responses. The following is a summary of these 

findings. 

The primary factors found to affect bicyclists’ perceived LOS were: 

• Path width. 

• Active passes (frequency of encountering and passing other users in the same direction). 

• Meetings (frequency of encountering other users in the opposite direction). 

• The presence of a striped centerline. 

The frequency of active passes and meetings were determined by user mix (mode split) and the 

overall user volume on the trail. 

As a result of the survey, bicyclists’ LOS was shown to be most affected by sharing a trail with 

slower users. Pedestrians had the greatest negative impact, because they had the slowest average 

speed. For example, a bicyclist traveling at 19.3 kilometers per hour (km/h) (12.0 miles per hour 

(mi/h)) faced an impediment when encountering a pair of pedestrians traveling at 4.8 km/h (3.0 

mi/h) or a runner traveling at 9.76 km/h (6.0 mi/h). During these encounters, the bicyclists 

executed passing maneuvers to maintain speed. 

Encountering significant numbers of slow moving users in the same direction of travel increased 

the need to make passing maneuvers. Encountering significant numbers of slow moving users 

traveling in the opposite direction tended to block the space needed to make passing maneuvers. 

Width played a factor in determining how much space was available to make passing maneuvers, 

and the presence of a striped centerline was also found to affect the bicyclist’s sense of freedom 

to maneuver. 

In summary, bicyclists’ LOS decreased when: 

• The need to pass other users increases. 

• The amount of space available to make a passing move decreases. 

• The probability that a passing opportunity will be blocked by other users increases. 

Factors found to have little or no effect on the bicyclist’s operational comfort include the 

following: 
11

• Trail setting. 

• Lateral clearance. 

• Sight distance. 

• Presence of a shoulder. 

• Presence of horizontal curves. 

Each of the factors listed above was evaluated only within the range of variation extant among the 

15 study trails (see appendix A for details). Within those ranges of variance, these factors were 

not found to be statistically correlated to the LOS ratings given by the participants in the user 

perception survey. 

13

3. LOS FOR SHARED-USE PATHS 

WHAT IS LOS? 

For motor vehicles on roadways, HCM defines LOS as a “quality measure describing operational 

conditions within a traffic stream, generally in terms of such service measures as speed and travel 

time, freedom to maneuver, traffic interruptions, and comfort and convenience.”(3) HCM defines 

six levels of service for a particular facility type and uses letters A to F to represent them, from 

best to worst. Each LOS represents a range of operating conditions. Safety is not explicitly 

included in the measures that establish motor vehicle LOS. 

The trail LOS model developed through this research is similar to that which is used for motor 

vehicle LOS. Listed below are some key similarities and differences. 

Similarities include: 

• The trail LOS model uses six levels of service categories and the letters A to F are used to 

represent them, from best to worst. 

• Maintaining an optimum speed (for the bicyclist) is a key criterion. 

• Service measures are primarily related to freedom to maneuver. These include meetings, 

active passes, delayed passes, and the perceived ability to pass. 

• Safety is not included in the set of measures that establish service levels. 

The key difference is: 

• Trail LOS does not factor in travel time or traffic interruptions such as signals or stop 

signs at grade crossings. 

It is important to note a host of other factors the reader may want to consider in a trail users’ 

assessment of comfort and enjoyment of a trail, such as the following: 

• Pavement/surface condition and materials. 

• Weather. 

• Frequency and design of curves. 

• Presence and degree of grade changes (hills). 

• Proximity to adjacent motor vehicle traffic. 

• Quality of scenery. 

• Physical setting. 

• Quality of bicycling equipment in use. 

• Perceived safety of the surrounding neighborhood. 

Just as motor vehicle LOS measures a limited aspect of the experience of driving and does not 

take into account the quality of the vehicle in which a person travels, the scenery along the road, 

etc., the trail LOS model has similar limitations. While such factors of trail design are important 

to the user’s experience, they will be left to further research. 

THE SHARED-USE PATH LOS MODEL 

The Shared-Use Path LOS (SUPLOS) model is a mathematical formula that uses select inputs 

describing conditions along a trail to calculate an LOS score. A key task in model development 

was to determine what inputs should be used and what mathematical relationships existed among 
14

them. The goal was to develop a formula that would yield scores consistent with the evaluation of 

similar conditions made by participants in the perception survey. A secondary objective was to 

use only those inputs that are truly necessary and most readily available. 

Using a variety of statistical methods, the operational and user perception survey variables were 

examined to evaluate which variables had the most influence in determining the grades users gave 

to the different conditions represented in the video clips. A model (mathematical equation) was 

built that would use the most significant factors as inputs to generate LOS scores and grades. The 

model was tested and adjusted to ensure that it generated grades that closely correlated to the 

perception scores that trail users gave each video clip. 

The equation in figure 1, below, is the basic SUPLOS model. Appendix B provides additional 

details about the factors used in the model. For a complete explanation of the derivation of the 

model see chapter 7 of the Final Report.(8)

Figure 1. Equation. Basic SUPLOS model. 

Where: 

 E = Events = Meetings per minute + 10 (active passes per minute) 

 RW = Reciprocal of path width (i.e., 1/path width, in feet) 

 CL = 1 if trail has a centerline, 0 if trail has no centerline 

 DPF = Delayed pass factor 

The SUPLOS model generates a LOS score between zero and five. Table 5 describes the 

SUPLOS scale, which shows how raw scores correspond to letter grades. An A is the highest 

score, excellent, and an F is the lowest score. 

Table 5. SUPLOS scale. 

LOS Score 

 X ≥ 4.0 

3.5 ≤ X < 4.0 

3.0 ≤ X < 3.5 

2.5 ≤ X < 3.0 

2.0 ≤ X < 2.5 

 X < 2.0 

LOS Grade

A 

B 

C 

D 

E 

F 

Best 

Worst 

INTERPRETING SHARED-USE PATH LOS GRADES 

In general, grades A–C can be considered acceptable levels of service and D–F can be considered 

degraded levels of service. The LOS descriptions in table 6 provide a more refined framework. 

A benefit of this LOS model is that it provides a uniform quantitative measurement for use 

throughout the United States and North America. However, each political jurisdiction and trail 

managing agency certainly has latitude to adopt different policies covering acceptable levels of 

service for trails within their own communities, as is the case with roadway levels of service. To 

SUPLOS = 5.446 – 0.00809(E) – 15.86(RW) – 0.287(CL) – (DPF) 
15

some degree, determining what scores and grades are acceptable can vary for each different 

application of the model. For example, a jurisdiction may elect to establish a policy to ensure that 

new trails meet a higher performance standard than the standard considered acceptable for 

existing trails. 

Table 6. Interpreting SUPLOS grades. 

A: Excellent. Trail has optimum conditions for individual bicyclists and retains ample space to 

absorb more users of all modes, while providing a high-quality user experience. Some newly 

built trails will provide grade-A service until they have been discovered or until their 

ridership builds up to projected levels. 

B: Good. Trail has good bicycling conditions, and retains significant room to absorb more users, 

while maintaining an ability to provide a high-quality user experience. 

C: Fair. Trail has at least minimum width to meet current demand and to provide basic service 

to bicyclists. A modest level of additional capacity is available for bicyclists and skaters; 

however more pedestrians, runners, or other slow-moving users will begin to diminish LOS 

for bicyclists. 

D: Poor. Trail is nearing its functional capacity given its width, volume, and mode split. Peakperiod travel speeds are likely to be reduced by levels of crowding. The addition of more 

users of any mode will result in significant service degradation. Some bicyclists and skaters 

are likely to adjust their experience expectations or to avoid peak-period use. 

E: Very Poor. Given trail width, volume, and user mix, the trail has reached its functional 

capacity. Peak-period travel speeds are likely to be reduced by levels of crowding. The trail 

may enjoy strong community support because of its high usage rate; however, many 

bicyclists and skaters are likely to adjust their experience expectations, or to avoid peakperiod use. 

F: Failing. Trail significantly diminishes the experience for at least one, and most likely for all 

user groups. It does not effectively serve most bicyclists; significant user conflicts should be 

expected. 

LOS SCORES FOR 15 STUDY TRAILS 

Table 7 provides LOS scores and grades for 15 trails studied as part of this research. This table 

includes two-way and one-way user volumes, mode splits, trail widths, and presence of centerline 

variables. It also provides a data profile for the average trail and its corresponding LOS score and 

grade (3.15, C). 
16

Table 7. Study trail level of service grades and characteristics. 

Trail User Type Mode Sp

Path Name LOS Score LOS Grade 

Total 

Two-Way 

Volume 

(per hour) 

One-Way 

Volume 

(per hour) 

Trail 

Width 

(ft) 

Centerline Adult Bikes Pedestrians Runners 

Pinellas Trail 4.05 A 120 60 15.0 Yes 81.4 4.6 2.3 Honeymoon Island Trail 3.78 B 110 55 12.0 No 22.9 54.2 12.5 White Rock Lake Trail 3.75 B 252 126 14.0 Yes 71.6 13.6 8.0 Grant's Trail 3.72 B 122 111 12.0 Yes 59.2 16.3 4.1 W&OD Trail 3.50 B 44 22 10.0 Yes 73.7 5.3 15.8 Sammamish River Trail 3.31 C 418 209 10.0 No 78.9 3.4 3.4 Minuteman Bikeway 3.30 C 442 221 12.0 Yes 51.9 6.2 15.6 Capital Crescent Trail 3.15 C 159 80 10.0 Yes 55.9 17.0 18.6 White Creek Trail 3.07 C 216 108 8.0 No 64.8 9.9 6.6 South Bay Trail 2.39 E 616 308 14.0 Yes 40.3 17.4 12.5 Charles River Bike Path 2.37 E 438 219 8.0 Yes 72.3 8.2 3.8 Forest Park Trail 2.17 E 299 150 10.0 Yes 33.0 24.4 27.8 Mill Valley—Sausalito Pathway 1.94 F 641 320 9.5 No 62.8 7.8 27.8 Lake Johnson Trail 1.61 F 205 102 8.0 No 14.1 63.3 21.9 Lakefront Trail 0.0 F 2320 1160 20.0 Yes 48.8 20.5 17.7 Average Trail† 3.15 C 311 105 11.0 Yes 55.0 20.0 10.0 

 1 ft = 0.3 m † The profile of the Average Trail was created by averaging the data for 13 of the 15 study trails. The high and low volume trails (W&OD and Lakefromix and the data of the remaining trails was averaged. The mode splits were rounded to the nearest increment of five. 
17

4. APPLYING THE MODEL TO YOUR TRAIL 

The SUPLOS model is applicable to a variety of trail planning and design problems related to 

crowding and to accommodating diverse user groups. It is especially useful for trail planning and 

design tasks that need to augment qualitative criteria with quantitative measures to strengthen the 

basis for making trail design decisions. The following is a list of potential uses for the analysis tool: 

• 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, an 

unusually high-use area, or an area with many reported user conflicts. 

To enable the easy use of the model by practitioners, it has been programmed into a spreadsheet 

tool called the Shared-Use Path LOS Calculator. The spreadsheet tool provides the LOS for a 

path segment based on only four inputs from the user: estimated or counted one-way user volume 

in the design hour, mode split percentages, trail width, and presence or absence of a centerline. 

This chapter will help the reader understand how to apply this tool effectively and to generate 

results that are appropriate for the particular problem at hand. To make the best use of the 

calculator, it is important to understand the limits of its application and how contextual factors 

should be considered when collecting or structuring the input data. 

LINK ANALYSIS 

The SUPLOS model is a link analysis tool designed to provide an LOS evaluation for a particular 

link or segment of a linear trail. It is not designed to evaluate trail/roadway intersections, rest 

stops, or trailheads. It only provides LOS along a particular segment of pathway. 

In general, segment length is not a limiting factor in selecting a link for analysis. The key to 

determining how much trail can be evaluated with one calculation is whether or not the trail 

conditions and use characteristics remain the same over the entire length that has been selected. 

However, because of the limits of the data used to calibrate the model, trail segments under a 0.40 

km (0.25 mi) are not recommended for analysis. Moreover, because typical trip distances for 

some trail users are limited, and user turn-back rates will begin to undermine the accuracy of 

volume and mode split data on longer segments, 3.2–4.8 km (2.0–3.0 mi) is the recommended 

maximum segment length. 

Each practitioner should exercise professional judgment in making these decisions. To aid that 

effort, the following list of conditions and characteristics should remain roughly the same over 

the entire distance of trail being considered as one link (segment): 

• Trail width. 

• Trail user volume. 

• Trail user mix (mode split). 

• Presence of a centerline stripe. 
18

• An absence of significant flow interruptions such as stop signs, signalized road crossings, 

or other grade crossings (see box below). 

• An absence of spur trails, trailheads, or other access points that may significantly affect 

user volumes or mix. 

If any of these characteristics change significantly over the length of a trail segment, it is 

recommended that the segment be divided into one or more links using road crossings, access 

points, or other locations where characteristics change as endpoints for the smaller segments. 

Moreover, when considering establishing a trail volume and user mix profile for a single segment 

that is longer than 1.6 km (1.0 mi) based on counts taken in only one location, it is important to 

determine if turn-back rates for pedestrians or other users might be significant enough to affect 

the accuracy of this data for the sections of the segment that are farthest from the data collection 

point. In other words, if users often turn around partway through, a single count may not 

represent the whole segment very well. 

As with any model, the quality and accuracy of the output can be no better than that of the inputs. 

It is understood that the quality and accuracy of input data will vary for each user of the tool. 

Moreover, each user and/or situation does not demand a uniform level of accuracy to produce a 

useful result. For these and other reasons, professional judgment is critical in determining what 

level of accuracy is required for the data to be used in any particular application. In most 

situations, slight variations in data may not affect LOS scores significantly, and the tool itself can 

be used to test variations in data and to determine what impact they have on LOS results. 

Flow Interruptions 

The SUPLOS model does not factor in potential delay and other impacts from stop signs, 

signalized road crossings, or other grade crossings that interrupt the flow of trail traffic. The 

model is designed to generate LOS scores for trail segments of 0.40 km (0.25 mi) or longer with 

no flow interruptions. If LOS is desired for a length of trail that includes these types of 

interruptions, the trail should be segmented at these locations, and if possible, separate volume 

and mode split data should be developed for each segment. 

DATA REQUIREMENTS 

Only four data inputs are needed for the model to generate an LOS score and grade-trail width, 

presence of a centerline, one-way user volume and mode split. The following discussion of data 

requirements is provided to help readers apply the tool correctly and effectively to their unique 

situation. 

Trail Width 

Trail widths should be measured in feet. Widths may be entered in half-foot increments, i.e., 8.0, 8.5, 

9.0, etc. (1 ft = 0.305 m). The model is calibrated to address widths between 2.4 m and 6.1 m (8.0 ft 

and 20.0 ft). Widths greater or lesser than these amounts will produce score and grade outputs; 

however, the model is not designed to address widths outside a range of 2.4–6.1 m (8.0–20.0 ft).*

 

 

*

 The Guide for the Development of Bicycle Facilities (AASHTO, 1999) established 2.4 m (8.0 ft) as the minimum 

recommended width for shared use paths. The widest trail included in this study was the 6.1 m (20.0-ft) Lakefront Trail 

in Chicago, IL; the model is not designed to address widths outside these minimum and maximum boundaries. 
19

Centerline 

Centerline is a yes/no input, to be based on the existing striping pattern of each test segment or 

the proposed striping pattern for an unbuilt trail. 

Trail User Volume 

The volume data needed for the calculator can be provided in one of three ways, depending on 

how the tool is being applied: 

• By using actual volume counts collected on an existing trail. 

• By using estimated volume counts developed by extrapolating from actual volume data 

gathered on another trail that is determined to be similar to the test trail (this can be one 

of the trails addressed in this study). 

• By developing projected user volumes such as for an unbuilt trail, where LOS 

calculations will be used to aid in the trail planning and design process. 

Whether volume data are developed from estimates or actual counts, they should be structured, or 

restructured, in the following ways: 

• One-way trail volume should be calculated for each separate segment (link) of trail for 

which an LOS score is desired. If counts are structured as total two-way volumes, an 

assumed 50/50 directional split is recommended for conversion to one-way volumes. 

Volume data should be expressed in users per hour. 

• Volume data should include a total count of all user types (modes) that use the treadway 

being evaluated. If a separate parallel treadway such as a jogging track or equestrian trail 

exists in the same trail corridor, users on this treadway should not be included in the 

volume or user mix data used in the model. 

• If new user counts are collected for use in this tool, it is recommended that a minimum of 

three two-way, hourly counts be taken on each trail segment for which an LOS score is 

desired. For each test trail segment, an average, one-way, per-hour volume can be created 

from the three, two-way hourly counts. 

If actual user volume is not known and estimates need to be developed, options include: 

1. Use the volume data collected on another trail in your community or region that is 

sufficiently similar to the one you wish to analyze. 

2. The one-way trail volume for the average trail can be used. This can be accomplished by 

using the volume number provided in the SUPLOS model itself; also see the average trail 

in table 4. 

3. Review the trail volumes of the 15 study trails (see appendix A and table 4), and use the 

volume from a study trail that seems to be similar to the trail you wish to analyze, i.e., if 

it is located in a similar community, has a similar setting, has a similar width, has a 

similar mode split, etc. 

Trail User Mix (Mode Split) 

Mode split is expressed as a percentage of one-way trail users per hour. The model provides the 

opportunity to input a mode split percentage for up to five different modes: adult bicyclists, 

pedestrians, runners, in-line skaters, and child bicyclists. Mode split inputs can be round numbers 
20

or precise numbers using one decimal place. They need to add up to 100 percent, exactly. Zero is 

an acceptable entry for any mode. Given the entire set of user types that are found on shared-use 

paths, these 5 categories were developed based on the actual users that were observed on the 15 

study trails. 

Other users, such as push scooters, electric scooters (used by disabled persons), wheelchairs, etc., 

may be present or expected on trails where this tool is applied. If the mode split data being used 

for the test trail segment include a breakout of user percentages in categories other than the five 

used by the calculator, those additional categories should be added to one of the five modes used 

by the calculator; use the mode that has the closest corresponding travel speed. †

 For average 

travel speeds, see table 4. 

If actual mode splits are not known and estimates need to be developed, options include: 

1. Use mode splits from data gathered on another trail in your community or region that are 

sufficiently similar to the one you wish to analyze. 

2. Use the mode split for the average trail. This can be accomplished by clicking a special 

button in the calculator spreadsheet labeled default mode split. 

3. Review the mode splits of the 15 study trails (see appendix A and table 2) and use a mode 

split from one of the study trails that you judge to be similar to the trail you wish to 

analyze, i.e., if it is located in a similar community, has a similar setting, has a similar 

width, etc. 

Spatial and Behavioral Factors That Affect Volume and Mode Split Data 

On many trails, user volumes and mix will vary considerably along different segments. When 

more accurate LOS scores are desired, trail segmenting should account for these variations. The 

following is a list of spatial and behavioral factors that can generate significant volume and mode 

split fluctuations and can be used to guide segmentation: 

• Locations of trail access points, including junctions with other trails, spur trails, 

trailheads, park nodes along a trail, and access points between the trail and adjacent trip 

generators and destinations. 

• Trip generators and destinations associated with points of access, such as housing 

developments, employment centers, schools, parks, university campuses, entertainment 

attractions, or other institutions or public properties. 

• Typical trip lengths and turn back rates; these will vary by user type and from trail to 

trail, because they are influenced by a number of trail specific factors such as trail layout, 

trip purposes, landscape character, and the personal habits and needs of local trail users. 

Additionally, when new user counts are planned, these factors may be used to inform the location, 

frequency, and timing of the counts. When volume and mode split estimates are being used for 

model inputs, the factors listed above may be used to make adjustments to the estimates to 

increase data accuracy. 

 

†

 However, because the model does not address the unique characteristics of equestrians, cross-country skiers, 

snowmobiles, or motorized all-terrain vehicle (ATV) trail users, counts of these users should not be included in any of 

the five categories or in the user volume totals. 
21

Temporal Factors That Affect Volume and Mode Split Data 

Temporal factors such as season of the year, day of the week, and time of day may be the most 

significant factors affecting trail user volumes. Therefore, any LOS calculated by the model 

applies only to the timeframes in which the volume data counts were taken. 

In most cases, trail analysts seek to understand trail operations under highest-use conditions. 

When this is the case, the volume data to use in the calculator should reflect those conditions. The 

volume data should be gathered during, or adjusted to reflect, the typical highest-use times. The 

exact number and duration of user counts needed to fully describe highest-use conditions may 

vary from case to case, depending on the level of detail desired for the volume profile and on how 

the resulting LOS score is to be used. 

To make a decent accounting of the variation in user volumes one might expect on a trail, at least 

three one-hour counts are recommended for each trail segment evaluated. Assuming that the 

purpose of the LOS scores is to determine if and how to improve service during high-use periods, 

counts should be taken during the high-use season, on a high-use day(s), and at high-use times of 

the day. 

In some cases, a trail manager’s problem may center as much on determining the duration or 

extent of high-use periods as on the decline of LOS during high-use times. Poor levels of service 

experienced during a few weekends a year or for an hour or two on a weekend day may be more 

tolerable than if a trail is crowded all day long throughout the spring, summer, and fall. The 

duration of time that certain levels of service exist may be as important to know as the LOS score 

itself. In these cases, the volume data used in the calculator should be more extensive and reflect 

greater temporal diversity. 

Some users of this tool may seek an LOS evaluation for a more specific purpose such as 

determining the LOS for bicycle commuters during an afternoon peak. In such a case, the data 

would be gathered on weekdays during the season(s) that generates the highest commuting rates 

and would focus on the particular afternoon hours when bicyclists are present on the particular 

trail segments. 

ASSUMPTIONS AND DEFAULTS 

This section describes the key assumption and default values built into the Shared-Use Path LOS 

Calculator and look-up tables in appendix C. Any of these values may be changed in the detailed 

spreadsheets of the calculator if the user has more specific information on hand. 

Directional Split 

The SUPLOS model assumes a 50/50 directional split. 

User Speed 

The model uses the average speeds and standard deviations for each user as shown in table 7. The 

default speed for the test bicyclist is 20.6 km/h (12.8 mi/h), which is the same speed as the 

average bicyclist. 

Peak-Hour Factor 

The model uses a default peak-hour factor (PHF) of 0.85. This factor was calculated using the 

data collected on the study trails. PHF is based on the observed one-way volume for the peak 15 

minutes within the 1-hour volume count. The model applies a PHF of 0.85 to the one-way, per-
22

hour user volume, which results in a volume boost of 17.6 percent. This factor ensures that the 

model results are responsive to typical flow peaking conditions found on trails. 

Operational Patterns and the Delayed Pass 

This and other trail research has found that bicyclists on trails tend to operate in distinct lanes, 

whether or not lanes are indicated on the trail surface with striping. Typical operational patterns 

include two-lane, three-lane, and four-lane operations: 

• In two-lane operations, passing maneuvers are made in the opposing lane. 

• In three-lane operations, each direction of travel shares use of a middle lane for passing 

maneuvers. 

• In four-lane operations, each direction of travel has its own passing lane. 

Because no standards exist that correlate trail width with lane operations, this study assumed the 

correlations shown in table 8. The widths in table 8 roughly correlate with the AASHTO Bicycle 

Facility Design Guide’s recommended 1.2-m (4.0-ft) minimum allocation of space for safe 

bicycle operation. 

Table 8. Correlation of trail widths 

and operational lanes. 

Width (ft) Lanes 

8.0–10.5 2 

11.0–14.5 3 

15.0–20.0 4 

1 ft = 0.3 m 

Lane configuration matters only in the model’s calculation of a delayed-pass factor. The model 

automatically determines the correct lane configuration to use based on trail width, as shown in 

table 8. The delayed pass factor is computed differently for each of the three possible lane 

configurations using the overall trail volume, mode split, and average travel speeds to calculate 

the probability of encountering delay in a passing maneuver: 

• Two-lane operation has the greatest potential for creating delayed passes because the 

bicyclist must use the opposing lane to pass a slower user, and that lane may be occupied 

by users traveling in the opposite direction. 

• Three-lane operations provide the bicyclist with better conditions for passing slower 

users because of the presence of a center, shared passing lane. Delay is determined 

primarily by the likelihood that a trail user traveling in the opposite direction is already 

using the center lane to make a passing maneuver; there is less likelihood of delay than in 

two-lane operation. 

• Four-lane operations provide still better passing conditions because, unless overall user 

volume is extremely high, the probability of a delayed passing maneuver is greatly 

reduced. 

SHARED-USE PATH LOS LOOK-UP TABLES 

Appendix C includes a series of look-up tables that have been developed to provide readers a 

quick reference for LOS grades and volumes. 
23

Tables 12 through 14 (see appendix C) provide LOS grades for a variety of volumes and trail 

widths using the average trail mode split, a high bicycle share mode split, and a high pedestrian 

share mode split, respectively. Tables 15 through 17 provide maximum service volumes for each 

LOS grade for a variety of trail widths. Service volumes are the volumes at the boundaries 

between levels of service. Again, three mode split examples are provided: average trail, high 

bicycle share, and high pedestrian share. 

25

5. INSTRUCTIONS FOR USING THE SHARED-USE PATH 

LOS CALCULATOR 

INTRODUCTION 

The Shared-Use Path LOS Calculator is provided in the form of a spreadsheet. Programmed with 

the complete LOS model, it provides a one-page, user-friendly interface (worksheet) that allows 

the user to analyze up to five data sets. The calculator requires only four inputs to generate an 

LOS grade—trail width, presence of a centerline, trail user volume, and mode split for up to five 

user types (adult bicyclists, pedestrians, runners, in-line skaters, and child bicyclists). 

The calculator is programmed in a Microsoft Excel ®TM spreadsheet file (filename: 

SUPLOS_Calculator_FHWA_2004) that can be acquired by downloading the file from the 

website of the U.S. Department of Transportation (USDOT) supported Pedestrian and Bicycle 

Information Center (www.bicyclinginfo.org or www.walkinginfo.org), or by ordering it on CDROM from the Information Center. 

The calculator provides five data entry rows in which LOS can be tested on as many as five 

different trails or trail segments. Analysis scenarios can include different trails or diverse 

segments of the same trail. For details about the lengths of trail to which LOS calculations can be 

applied, see the box below. 

Trail Length and LOS Calculations 

Because the SUPLOS model is a link analysis tool, any single LOS score applies only to a trail 

segment having consistent width, striping, volume, and mode split characteristics throughout. A 

test segment must be at least 0.40 km (0.25 mi), but can be a number of kilometers (miles) long if 

the same input values are valid over the entire segment and there are no trail flow interruptions 

(stop signs, signals, or at-grade crossings) within the segment. The presence of flow interruptions, 

points of access (that significantly diminish or increase the volume, or change the mode split), or 

changes in trail width or surface will necessitate segmenting the trail for the purposes of LOS 

evaluation, and each segment will need its own unique set of input data. 

STEP-BY-STEP INSTRUCTIONS 

The Shared-Use Path LOS Calculator should be opened in Excel. Enable Macros should be 

selected in the first dialogue box. If not already selected, the Trail_LOS_Calculator tab at the 

bottom of the window should be selected. This will open the calculator worksheet. 

The calculator provides five data entry rows in which LOS can be tested on as many as five 

different trails or trail segments at one time. The first row of the calculator includes example data 

for a typical trail, based on the average volumes and mode splits found on the 15 trails included in 

this study. 

Entering Data 

Before beginning the data entry process, review the previous chapter and the discussion about 

data requirements. Based on that discussion, assemble the data necessary to conduct your 

analysis. 

1. The first column provides a cell to enter the trail or segment name. Type in a name or 

segment identifier. 
26

2. The second column provides a cell for trail width. Enter a number representing the 

desired width in feet. Widths may be entered in 0.5-ft increments, i.e., 8.0, 8.5, 9.0, etc. 

(1 ft = 0.305 m). 

3. The third column asks if the trail has (or will have) a centerline. Type in a 1 for yes or a 0 

for no. 

4. The fourth column provides a cell for one-way trail volume per hour. Enter a 

representative number. 

5. Columns five through nine provide cells for mode split. Entries may or may not use 

decimal increments in tenths. (Decimal increments in hundredths should be rounded to 

tenths.) The sum of the 5 mode splits should total exactly 100, or an error message will 

appear above the data entry row. 

6. Data entries cannot be made in any of the spreadsheet cells other than those described 

above. 

Once all of the numeric inputs are entered, columns 11 and 12 will automatically calculate the 

LOS score and provide an LOS grade. 

Interpreting Results 

In the upper right-hand corner of the spreadsheet, a scale is provided that correlates the score with 

the appropriate grade. In general, grades A–C represent acceptable levels of service, whereas D–F 

are degraded levels of service. See chapter 3 for a full discussion on interpreting LOS grades. 

Copying and Printing Results 

The calculator worksheet provides five data entry rows to test LOS on as many as five different 

trails or trail segments at one time. Once five scenarios have been entered, the whole sheet may 

be copied or converted to a word processing or spreadsheet file to create a permanent record of 

these cases and results. Once the information has been pasted into a new file, revision of model 

calculations will not be possible in that new document. 

Using the regular print commands, the results may be printed directly from Excel or by printing 

the file to which copies have been saved. 

By copying and saving the results to another file, the calculator can be used multiple times 

without losing the results of previous scenarios. 

Returning to the Default Mode Split 

For convenience, the calculator worksheet has been designed with a separate one-click button to 

reset the default mode split for each row. 
27

6. IMPLICATIONS OF THIS RESEARCH FOR TRAIL DESIGN 

The central findings of this study have important implications for trail design. The following is a 

list of key findings that can be used to inform design choices: 

1. Width is the key factor in determining LOS, and every additional foot of trail width has a 

positive impact on LOS. 

2. Bicyclists’ LOS on pathways is very sensitive to user mix; when the amount of foot 

traffic (runners and pedestrians) surpasses 15 percent of trail use, bicyclists’ LOS is 

significantly impacted. 

3. Bicyclists are affected by a centerline stripe dividing directional flows. 

TRAIL WIDTH 

The findings of this study provide strong support for the standard trail width guidance provided in 

the AASHTO Guide for the Development of Bicycle Facilities.

(2) Trails having 2.4-m (8.0-ft) 

width, which AASHTO recommends only in “rare instances,” were found to have poor LOS, 

except at very low volumes or with user mixes that included few pedestrians and runners. The 

findings of this research support AASHTO’s minimum “recommended paved width for a twodirectional shared-use path of [3.0 m] ten feet.” *

The study found that widths of 3.4–4.6 m (11.0–15.0 ft) provide improved LOS for higher 

volumes and more balanced user mixes than narrower widths. This is consistent with AASHTO 

recommendations that “under certain conditions it may be necessary or desirable to increase the 

width of a shared-use path to 3.8 m (12.0 ft) or even to 4.3 m (14.0 ft), due to substantial use by 

bicycles, joggers, skaters and pedestrians, ....”†

 Trails of 3.4–4.6 m (11.0–15.0 ft) are wide 

enough to operate as three-lane paths. The increased passing capacity provided by a trail that 

operates as three lanes improves LOS and increases the trail’s ability to absorb higher volumes 

and more diverse mode splits without severely degrading service. 

Design Implications—Width 

• During design of new trails and widening of existing trails, designers may want to 

consider varying the trail width to achieve LOS goals in key locations but not overbuild 

in other locations. Adding width to improve LOS is valuable to trail users, even if it is 

provided only on selected segments. 

• When considering wider trails, designers and decisionmakers may want to think in 0.3-m 

(1-ft), rather than 0.6-m (2.0-ft), increments. Typical practice has been to consider trail 

widths in 0.6-m (2.0-ft) increments. Using this approach may miss opportunities to 

provide measurable increases in LOS while at the same time containing costs and 

minimizing environmental impacts. 

CENTERLINE STRIPING 

A striped centerline was found to have strong impact on the bicyclist’s perception of freedom to 

maneuver. This finding appears to support the intent of trail designers in providing a centerline, 

which is clear delineation of opposing travel lanes. A centerline reinforces the idea that, to pass a 

 

* Guide for the Development of Bicycle Facilities, AASHTO, 1999, p. 35. 

†

 ibid, p. 36. 
28

slower-moving user, the cyclist may need to use the travel lane of opposing trail users and should 

pass only when the opposing lane is open. 

This research found that the presence of a centerline stripe results in a significant reduction in the 

LOS. It appears that bicyclists may feel less comfortable making a same-direction passing 

movement when a centerline stripe is present. While this finding might appear initially to mean 

that a centerline stripe degrades pathway LOS and should not be used, it is important to note that 

there may be other valid safety reasons for providing a centerline stripe, particularly on crowded 

trails, on curves with limited sight distance, and in other appropriate circumstances. 

MULTILANE STRIPING 

Only two trails in this study were striped with more than two travel lanes. The Pinellas Trail was 

striped as a three-lane trail, with one lane in each direction for bicycles and skaters and one lane 

for pedestrians. The Lakefront Trail was striped as four lanes, with two lanes in each direction. 

These two examples did not represent a sufficient number of study trails to fully assess the impact 

of multilane striping patterns on LOS. However, it is likely that having sufficient trail width for a 

four-lane operation (a minimum of 4.6 m (15.0 ft)) increases the ability of bicyclists to pass 

slower-moving users without encountering blockage from trail users in the opposing lanes. 

MULTIPLE TREADWAYS 

A number of shared-use trails have been designed with two treadways in the same trail corridor. 

Often, one is paved and the other is a soft surface. Frequently, one of the treadways is provided 

for exclusive use by one or two trail user groups, or user restrictions are imposed on both paths in 

an effort to segregate users. 

Given this study’s findings about the impact of user mix on bicyclist LOS, a multiple treadway 

design that effectively reduces the number of pedestrians and runners mixing with bicyclists will 

have significant LOS benefits for the treadway used by bicyclists. This study did not address 

compliance with use restrictions, an issue that is often raised by trail managers as a problem when 

separate treadways are provided. 

TRAIL OPERATIONS AND MANAGEMENT 

While this study did not examine issues related to trail operations and management, the 

framework of the tool may lend itself to applications in this area. Such possibilities might include 

the use of LOS grades in warrants for trail etiquette or warning signs. Trail etiquette signs address 

the sharing of treadways or the use of designated passing protocols. LOS may also be useful in 

setting trail speed limits or other advisory or regulatory protocols that will increase user safety 

and moderate user conflicts.
29

7. EXAMPLE APPLICATIONS: FICTIONAL CASE STUDIES 

CASE STUDY 1: TESTING DESIGN OPTIONS FOR THE STONE CREEK TRAIL 

UPGRADE 

Stone Creek Trail is located in the heart of Rockton, an old, eastern industrial city of about 

200,000 residents. The 25-year-old trail is located in a linear park that was developed along a 

large stream, Stone Creek. Downtown Rockton grew at the confluence of Stone Creek and the 

Rocky River. The trail is 8.8 km (5.5 mi) long and connects a number of the city’s finest 

neighborhoods with downtown. Along it are located an elementary and junior high school, a 

major playground, a small hospital, and a small liberal arts college. When it was last repaved 15 

years ago, it was widened from the previous 1.8-m or 2.1-m (6.0-ft or 7.0-ft) width to 2.4 m (8.0 

ft) throughout. 

In recent years, the city council and managing agency, Rockton Department of Public Works and 

Parks (DPW&P), have been receiving pressure to widen the trail even further. That pressure was 

coming from a number of community interests: 

• The Tourism Council and Historic Preservation League, which have been successful in 

boosting the city’s economy through historic preservation efforts focused on the old 

milling industry, the reuse of warehouses as small-scale breweries, and the town’s access 

to outdoor recreation activities in the nearby mountains. They wanted more and better 

outdoor recreation activities to be offered in town to keep tourist dollars coming into the 

city. 

• A group of parents who felt that the trail was unsafe because of its age, rough surface, 

and narrow width. In recent years, there have been a couple of bad crashes between trail 

users; these involved youths. Skaters, skateboarders, push scooters, strollers, and dog 

walkers are all common on the trail, in addition to bicycles and pedestrians. 

• A local environmental organization that recently joined with the local bicycle club to 

promote in-line skate and bicycle commuting to reduce downtown parking demand and 

keep the air clean. The trail seemed too narrow to accommodate more nonmotorized 

wheels, however, along with all of the pedestrians, kids, and a growing crowd of fitness 

walkers organized by the hospital. 

The Stone Creek Park Committee, a longstanding advisory committee for DPW&P, favors some 

widening but is wary of making the trail so wide that too many trees are lost and the 100-year-old 

park will become a speedway for wheels. There is concern that too many wheeled users will 

make the park and trail too scary for senior citizens and others (mostly walkers) who have cared 

for it for many years. Segregation of users is one possibility they are considering, but they are not 

sure users will comply. 

The question is this: How much more width is enough to satisfy the demand and how much is too 

much? An initial staff survey determined that, in most parts of the park, enough space exists to 

accommodate a trail of up to 4.3 m (14.0 ft) wide. The DPW&P staff and the committee would 

like to know what other communities in similar situations have done. However, even on the 

Internet, they had difficulty finding another community with enough similar characteristics that 

had already encountered and solved a similar trail problem. Then, in response to a call to the 

State, the Bicycle and Pedestrian Coordinator at the State department of transportation 

recommended the Shared-Use Path LOS Calculator, a new FHWA resource. 
30

Because the community had no existing trail counts, nor were any useful volume counts available 

from other multiuse trails in the State, it was necessary to gather fresh trail user counts to develop 

inputs for use of the tool. Volunteers from all of the interested stakeholder groups were 

organized, and they followed the trail count guidelines provided in the SUPLOS User’s Guide. To 

meet the data needs necessary for the results they wanted, the following data collection scope was 

adopted: 

• Collect data on three warm-weather Spring days in different weeks of May and early June 

(Friday, Saturday, and Sunday). 

• Take counts to cover the following time periods—three 2-hour periods on Friday 

(7–9 a.m., 12–2 p.m., and 4–6 p.m.) and 10 a.m.–4 p.m. on Saturday and Sunday. 

• Take counts at five locations along the trail, at midpoints between major access points. 

• Count children on skateboards, push scooters, and skates as pedestrians, the user type 

with the most similar speed profile. 

Figure 2, a screen capture from the Shared-Use Path LOS Calculator for this case, shows the 

results of the average weekend, one-way, per-hour, volume counts, and mode splits. Friday 

volumes were found to be about 50 percent lower and so were not used for the LOS calculations. 

As noted above, for data collection and analysis purposes, the trail was divided into five 

segments. Trail segments 1 and 2 scored F and E levels of service, respectively, while the other 

segments scored D, confirming suspicions that peak-hour conditions were deteriorating. It was 

easy for the staff and committee to imagine even worse conditions on summer weekends when 

more tourists were in town. 

Before various widths were tested, participants agreed that if the trail were widened, it should be 

done not only to improve conditions for existing users, but also to secure some additional 

capacity for future growth in trail use. 
31

 1 ft = 0.3 m 

Figure 2. Screen capture. Existing conditions LOS analysis. 

The following general LOS goal and design policy was adopted: 

• The LOS goal should be a high C or low B to ensure space for additional users. 

• A flexible design approach should be used to meet the needs of the users that are attracted 

to each segment. For example: 

o Segment 1 near downtown should have room to attract more users and provide a trail 

experience that tourists will want to repeat. 

o Part of segment 3 near the school and a popular playground attracts more youth and 

should be designed to support trail etiquette education. 

o Segment 5, which runs along the college campus, attracts more skaters and runners. 

ROW #1

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

Stone Creek 1 13.0 1 152.0 53.0% 24.5% 13.0% 7.5% 2.0% 100.0% 3.27 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #2

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 2 11.0 0 137.0 64.5% 19.5% 9.5% 5.0% 1.5% 100.0% 3.57 B

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #3

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 3 10.0 1 94.0 55.5% 13.5% 12.0% 9.0% 10.0% 100.0% 3.13 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #4

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS ScoreLOS Grade

SC 4 11.0 1 117.0 62.0% 11.5% 13.5% 9.5% 3.5% 100.0% 3.47 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #5

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 5 12.0 1 145.0 61.5% 8.0% 15.5% 13.0% 2.0% 100.0% 3.55 B

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

Trail LOS

Trail LOS

Trail LOS

Trail LOS

Trail LOS

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split
32

Using these guidelines, a variety of widths was tested in the calculator to see which achieved the 

desired levels of service. Figure 3, a screen capture from the Shared-Use Path LOS Calculator for 

this case, shows the widths and resulting LOS scores that were finally selected. 

 1 ft = 0.3 m 

Figure 3. Screen capture. LOS for selected design widths. 

Working with a trail design consultant, the widths in figure 3 and the general guidelines were 

used to develop five different cross-sections. Designs for segments 2 and 4 varied only in the 

centerline treatment, as a means to further test users’ response. Table 9 describes the final 

segment designs selected. 

ROW #1

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

Stone Creek 1 8.0 1 152.0 53.0% 24.5% 13.0% 7.5% 2.0% 100.0% 1.95 F

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #2

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 2 8.0 1 137.0 64.5% 19.5% 9.5% 5.0% 1.5% 100.0% 2.33 E

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #3

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 3 8.0 1 103.0 55.5% 13.5% 12.0% 9.0% 10.0% 100.0% 2.67 D

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #4

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 4 8.0 1 117.0 62.0% 11.5% 13.5% 9.5% 3.5% 100.0% 2.65 D

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

ROW #5

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

SC 5 8.0 1 145.0 61.5% 8.0% 15.5% 13.0% 2.0% 100.0% 2.58 D

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicylists.

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Trail LOS

Trail LOS

Trail LOS

Trail LOS

Trail LOS

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split
33

Table 9. Selected cross sections. 

Segment 

Number/Distance Width Shoulder Rationale 

1 / 0.75 mi 13 ft, centerline Grass The downtown section serves a 

heavy mix of pedestrians, tourists, 

and bicycle commuters. 

2 / 1.75 mi 11 ft, centerline 

only on curves 

Grass This section weaves through an 

especially cherished part of the park 

with many old trees and scenic 

settings along the stream; trail 

expansion needs to be kept to a 

minimum. 

3 / 0.75 mi 10 ft, centerline 2 ft of rolled 

stone dust on 

each side 

Because of its proximity to the 

schools, playground, and adjacent 

neighborhoods, this section should 

include a centerline and shoulders to 

facilitate youth education about trailsharing etiquette. 

4 / 1.00 mi 11 ft, centerline Grass This requires a transition design 

between segments; a separate soft 

surface jogging path could be added 

in the future. 

5 / 1.25 mi 12 ft, centerline Grass Width could be added to serve in-line 

skaters and higher overall user 

volumes from the college; segments 

4 and 5 can be promoted as ideal for 

skating as a way to draw skaters to 

this section of trail. A separate softsurface jogging path could be added 

in the future. 

1 mi = 1.6 km; 1 ft = 0.3 m 

CASE STUDY 2: TESTING DESIGN OPTIONS FOR THE DE SOTO RIVER 

WATERFRONT TRAIL 

The De Soto River Trail is a 7.2-km (4.5-mi) segment of multi-use trail proposed for the 

downtown waterfront in the city of New Metropolis. It will extend the existing De Soto River 

Trail, a 24.2-km (15.0-mi) trail system, from a nearby suburb into the heart of the city. New 

Metropolis is a city of 500,000 people in a metropolitan area of approximately 1.5 million. 

The Waterfront Trail has been an idea in the city’s comprehensive plan for many years; however, 

no action was taken until a waterfront revitalization effort brought the idea to prominence. 

Currently, a detailed waterfront redevelopment plan is underway and the city’s Office of Planning 

wants to ensure that the trail component of this plan establishes appropriate path design 

guidelines. Because it is the first major shared-use path to be built in the city for 25 years, the 

city’s transportation and park departments have no pre-existing guidelines and little trail 

experience. An advisory committee has been formed to assist the Office of Planning and 

revitalization consultants with the trail plan. 
34

The major question facing the Waterfront Trail Advisory Committee (WTAC) is this: How wide 

must the trail be to serve the volumes and diverse user groups expected? A WTAC member 

suggested using a new resource developed by USDOT-funded research called the Shared-Use 

Path LOS Calculator. The following discussion describes how WTAC used the calculator to 

inform their design process. 

After reading in the User’s Guide how the LOS concept should be applied to a trail with various 

access points, WTAC recognized that a LOS evaluation should be performed for three separate 

segments: 

• Segment A—3.2 km (2.0 mi) of path in newly acquired public lands that pass through a 

natural area slated to become an urban conservation area, with limited park development. 

This segment has no access points between the existing trailhead in Jefferson County and 

Reed Mill Park. 

• Segment B—a 2.4-km (1.5-mi) segment that passes through Reed Mill Park, the oldest 

park in the city, which is slated for revitalization and will serve as a major trailhead area. 

• Segment C—a 1.6-km (1.0-mi) segment that will be located in a new waterfront park to 

be built as an extension of Reed Mill Park. The new park is very close to downtown New 

Metropolis, which is expanding toward the river, now that upgraded flood control 

infrastructure is in place. From downtown to Water Street, the old warehouse district is 

being redeveloped with commercial and residential uses. The park will be about 0.40 km 

(0.25 mi) wide along the shoreline. Future expansion of the path 4.8 km (3.0 mi) downriver may be feasible if and when an old railroad line is abandoned. 

Given the history of the De Soto River Trail in neighboring Jefferson County, it seemed logical to 

employ trail usage data from that trail, at least as a starting point for volumes and user mixes that 

might be expected on the city’s section of the trail. 

The existing De Soto River Trail is a 3.0-m (10.0-ft) wide asphalt path. Counts taken the previous 

year show that the trail is averaging about 250 users per hour (total 2-way volume). The mode 

split for various trail user types was as follows: 

• Bicycles—51 percent. 

• Pedestrians—16 percent. 

• Joggers—19 percent. 

• Skaters—10 percent. 

• Other—4 percent. 

The volume data provided by Jefferson County were generated by taking counts every hour 

between 12:00 p.m. and 4:00 p.m. on one nice-weather weekend in both the spring and fall. The 

location where these counts were taken is just outside the city, along a 2.4 km (1.5-m) segment 

between a large trailhead near the city limits and a Jefferson County regional park facility in 

Jeffersonville (a suburb of 85,000 people). Based on this volume and mode split data, the 

calculator gave the existing De Soto River Trail in Jefferson County a LOS score of 2.81, which 

is a high D. 

Because the Waterfront Trail will be located in the city, which has higher population density and 

fewer trail opportunities than suburban Jefferson County, WTAC wants a plan to accommodate 
35

higher future-use levels. As a result, WTAC developed the following adjustments to the Jefferson 

County baseline counts, upon which to base assumptions for LOS analysis of segments A–C: 

• Each trail segment should be developed to meet a low-C LOS for projected 10-year 

volumes and mode splits as defined below. 

• Each trail segment has a different character and context; therefore, the 10-year 

projections and mode splits should vary accordingly: 

o Segment A, plus 20 percent of baseline, with fewer pedestrians and more bicycles. 

o Segment B, plus 50 percent of baseline, at the same mode split. 

o Segment C, plus 100 percent of baseline, with more pedestrians and fewer 

bicycles. 

• To accommodate additional increases in usage beyond these estimates, the trail should be 

designed with right-of-way reserved for expansion. 

• It is assumed that, in the first few years after a trail segment is built, the trail will 

experience user volumes lower than the baselines, and thus levels of service during those 

periods will be above C. 

• If the new trail is very popular from the start, it may need to exist at an LOS D for a 

period of years until expansion can be funded. 

Using these assumptions, the Office of Planning staff developed a series of volume and mode 

split estimates to use as inputs into the Shared-Use Path LOS Calculator to develop potential trail 

design cross sections for segments A–C of the Waterfront Trail, as shown in table 10. 

Table 10. Volume and mode split estimates to test in the calculator. 

Segment Assumptions 

(conditions) 

One-way 

volume per 

hour 

Bikes Peds Runners Skaters Child 

Bikes 

Existing trail 

in Jefferson 

County 

Experiencing 

some user 

conflicts 

125.0 51% 16% 19% 10% 4%

Segment A Same as above 150.0 56% 11% 19% 10% 4%

Segment B Same as above 187.5 51% 1% 19% 10% 4%

Segment C Same as above 250.0 40% 25% 20% 13% 2%

Various widths were tested in 0.2-m (0.5-ft) increments, starting at 2.9 m (9.5 ft). With each 

width change, the LOS score was observed to determine when a low-C (3.0-3.2) was achieved. It 

took 6.1 m (20.0 ft) width to get a low-C for segment C. Because 6.1 m (20.0 ft) was considered 

too wide a footprint, a multiple treadway design was considered that would provide pedestrians 

and runners with their own dedicated treadways. An 80 percent compliance rate was used for 

pedestrians and runners, and the user volume and mode splits were reduced accordingly. Figure 4, 

a screen capture from the Shared-Use Path LOS Calculator for this case, shows the results from 

the calculator after revising segment C for multiple-treadway options. 

Based on these results, WTAC adopted the following width design guidelines for each trail segment: 

• Segment A: Build a 3.4-m (11.0-ft) asphalt path, with AASHTO-recommended 0.6-m 

(2.0-ft) shoulders to be planted in grass. In natural areas, boardwalk sections may be 

reduced to a total clearance between railings of 3.7 m (12.0 ft). 
36

• Segment B: Build a 3.7-m (12.0-ft) asphalt path, with AASHTO-recommended 0.6-m 

(2.0-ft) shoulders to be planted in grass. 

• Segment C: For environmental and aesthetic reasons, building a path 6.1 m (20.0 ft) wide 

was not considered optimal or desirable. However, given the 0.40-km (0.25-mi) width of 

the waterfront park and the high volume that is expected in this segment near downtown, 

at least 6.1 m (20.0 ft) of width was determined to be desirable if it was provided in 

separate treadways, using space, landscaping, and elevation as buffers: 

o Closest to the river, a 1.8–2.4-m-wide (6.0–8.0-ft-wide) concrete promenade for 

pedestrians to stroll and observe the river (3.0–3.7 m (10.0–12.0 ft) wide for the 

expected highest-use segment). 

o Located away from the river, a 3.4-m (11-ft) asphalt path for bicyclists and skaters, 

with 0.4-m (1.0-ft) concrete shoulders and 0.6-m (2.0-ft) grass shoulders on each side 

(4.0 m (13.0 ft) of usable treadway) and a minimum 10.7-m (35.0-ft) buffer between 

path and promenade. 

o Located adjacent to the path (on the riverside), a 1.2-m (4.0-ft) soft surface trail for 

runners, with a minimum 1.5-m (5.0-ft) grass buffer. 

o Assuming an 80 percent compliance rate for pedestrians and runners using their 

separate treadways, the bicycle/skate path will provide a high LOS C (see segment C, 

revised, in figure 4). 
37

 1 ft = 0.3 m 

Figure 4. Screen capture. LOS for 10-year projected volumes and 

selected design widths. 

To ensure the potential to serve higher than expected volumes of trail users in the future, the 

following recommendations were included in the design guidelines: 

• For segment A: Identify a separate alignment for a 1.2–1.5-m (4.0–5.0-ft) hiker/runner 

path with a soft surface, to be developed if demand warrants. Because this is a natural 

area, if more capacity is ever needed, a natural surface pedestrian track should be created 

rather than expanding the paved treadway. To minimize the path footprint and visual 

impact in the natural area, the pedestrian track could be located away from the paved 

trail. 

• For segment B: Reserve sufficient right-of-way on the waterside of the main path to 

allow the development of a 1.8-m (6.0-ft) stone-dust pedestrian and runner path with a 

ROW #1

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

Jeff. County 10.0 1 125.0 51.0% 16.0% 19.0% 10.0% 4.0% 100.0% 2.81 D

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists.

ROW #2

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

Segment A 11.0 1 150.0 56.0% 11.0% 19.0% 10.0% 4.0% 100.0% 3.33 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists.

ROW #3

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

Segment B 12.0 1 187.5 51.0% 16.0% 19.0% 10.0% 4.0% 100.0% 3.13 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists.

ROW #4

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

Segment C 20.0 1 250.0 40.0% 25.0% 20.0% 13.0% 2.0% 100.0% 3.01 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists.

ROW #5

Segment Name Path Width Centerline

Closest 0.5 ft. 0=No Centerline Volume

Name Width (ft) 1=Centerline One-Way (per hour) Adult Bicyclists Pedestrians Runners In-Line Skaters Child Bicyclists All Modes LOS Score LOS Grade

C Revised 11.0 1 160.0 62.5% 8.0% 6.5% 20.0% 3.0% 100.0% 3.42 C

*Default mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists.

Trail LOS

Trail LOS

Trail LOS

Trail LOS

Trail LOS

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Mode Split (%)*

Volume (users per hour in 1 direction) and Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split

Click Here for Default Mode Split
38

minimum 1.5-m (5.0-ft) buffer between the two paths. The second path can be added if 

and when additional capacity is needed. It could also be paved if a hard surface will 

better meet users’ needs and if environmental impacts are acceptable.
39 

APPENDIX A. STUDY TRAIL PROFILES 

Lake Johnson Trail 

Raleigh, NC 

Trail Profile

 Trail length: 8.8 kilometers (km) (5.5 miles (mi)) 

 Community context: Suburban SE Raleigh, NC 

 Trail endpoints: Loop in Lake Johnson Park 

 Trail type: Park loop 

 Part of a trail system: Part of the Capital Area Greenway 

 Managing agency: Raleigh Department of Parks and Recreation 

Study Location Characteristics

 Study location: 0.40 km (0.25 mi) to 1.21 km (0.75 mi) 

 Landscape setting at study location: Wooded park, lake 

 Surface material: Asphalt (in poor condition) 

 Path width: 2.4–2.6 meters (m) (8.0–8.5 feet (ft)) 

 Improved shoulder: No 

 Centerline: No 

 Lane striping pattern: None 

 Other treadways in the corridor: None 

 Clear zone: 0.3–1.2 m (1.0–4.0 ft) 

 Landscape adjacent to clear zone: Wooded park, lake 

 Sight distance Poor 

 Curves: Medium 

 Slopes: Low 
40 

Sammamish River Trail 

Redmond, WA 

Trail Profile

 Trail length: 16.1 km (10.0 mi) 

 Community context: Suburban Seattle, WA 

 Trail endpoints: Blyth Park in Bothell, WA, and Marymoor Park 

in Redmond, WA 

 Trail type: Linear riverside greenway 

 Part of a trail system: Connects directly with the Burke Gilman Trail 

in Bothell, WA 

 Managing agency: King County Park and Recreation Division 

Study Location Characteristics

 Study location: In Sixty Acre Park, about 0.8 km (0.5 m) from 

NE 116th St. in Redmond, WA 

 Landscape setting at study location: Linear park, grass, and ballfields, adjacent to 

Sammamish River 

 Surface material: Asphalt 

 Path width: 3.0 m (10.0 ft) 

 Improved shoulder: No 

 Centerline: No 

 Lane striping pattern: None 

 Other treadways in the corridor: Horse trail 

 Clear zone: 1.8–3.0 m (6.0–10.0 ft) of short, mowed 

 grass 

 Landscape adjacent to clear zone: Linear park, grass, and ballfields, adjacent to 

Sammamish River 

 Sight distance Good 

 Curves: Low 

 Slopes: Low 
41 

Mill Valley—Sausalito Pathway 

Marin County, CA 

Trail Profile

 Trail length: 4.8 km (3.0 mi) 

 Community context: Suburban San Francisco 

 Trail endpoints: Harbor Drive in Sausalito, CA, and Alto Tunnel 

in Mill Valley, CA 

 Trail type: Rail-trail 

 Part of a trail system: A small component of the Bicentennial Bike 

Path and San Francisco Bay Trail; connects to 

popular on-street routes at each end 

 Managing agency: Marin County Department of Parks, Open Space 

and Cultural Services 

Study Location Characteristics

 Study location: At Bothin Marsh, north of the U.S. 101 bridge 

 Landscape setting at study location: Marsh, adjacent highway, bay 

 Surface material: Asphalt 

 Path width: 2.9–3.2 m (9.5–10.5 ft) 

 Improved shoulder: Yes; 5.0–7.0 ft of gravel 

 Centerline: No 

 Lane striping pattern: None 

 Other treadways in the corridor: None 

 Clear zone: 1.5–2.1 m (5.0–7.0 ft) gravel 

 Landscape adjacent to clear zone: Marsh, adjacent highway, bay 

 Sight distance Unlimited 

 Curves: Low 

 Slopes: No
42 

White Rock Lake Trail 

Dallas, TX 

Trail Profile 

 Trail length: 15.0 km (9.3 mi) 

 Community context: Urban NE Dallas, TX 

 Trail endpoints: Loop in White Rock Lake Park 

 Trail type: Park loop 

 Part of a trail system: Connects to the White Creek Trail on 

the north lakeside. 

 Managing agency: Dallas Department of Parks and Recreation 

Study Location Characteristics 

 Study location: Just south of the E. Lawther/Emerald Isle 

park access, near Winfrey Point 

 Landscape setting at study location: Open parkland, lake, park road 

 Surface material: 3.7 m (12.0 ft) of asphalt with 0.30-m (1.0-ft) 

concrete edges 

 Path width: 4.3 m (14.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Solid striped centerline; two 2.1-m (7.0-ft) 

lanes 

 Other treadways in the corridor: Some bicyclists use park road 

 Clear zone: 3.0–6.1 m (10.0–20.0 ft) grass, with 

some trees 

 Landscape adjacent to clear zone: Open parkland, lake, park road 

 Sight distance Unlimited 

 Curves: Low 

 Slopes: No 
43 

Lakefront Trail 

Chicago, IL 

Trail Profile

 Trail length: 39.4 km (24.5 mi) 

 Community context: Urban north Chicago, IL 

 Trail endpoints: Southside Chicago, IL, and Evanston, IL 

 Trail type: Lakefront beach trail 

 Part of a trail system: Connects to lakefront trail in Evanston, IL 

 Managing agency: Chicago Parks District 

Study Location Characteristics

 Study location: Near trail intersection with North Avenue 

 Landscape setting at study location: Public park and beach 

 Surface material: Concrete 

 Path width: 6.1 m (20.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Solid centerline and lane striping forming two 

interior 1.8-m (6.0-ft) lanes bounded by two 1.2-

m (4.0-ft) lanes 

 Other treadways in the corridor: None 

 Clear zone: Unlimited 

 Landscape adjacent to clear zone: Public park and beach 

 Sight distance Poor, due to heavy user volumes 

 Curves: No 

 Slopes: No 
44 

South Bay Trail 

Santa Monica, CA 

Trail Profile

 Trail length: 35.4 km (22.0 mi) 

 Community context: Suburban W. Los Angeles, CA 

 Trail endpoints: Santa Monica, CA, and Torrance, CA 

 Trail type: Oceanfront beach trail 

 Part of a trail system: Many connections 

 Managing agency: City of Santa Monica 

Study Location Characteristics

 Study location: About 1.6 km (1.0 mi) north of the Santa 

Monica Pier 

 Landscape setting at study location: Public beach 

 Surface material: Concrete 

 Path width: 4.37 m (14.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Dashed centerline 

 Other treadways in the corridor: None 

 Clear zone: Unlimited 

 Landscape adjacent to clear zone: Public beach 

 Sight distance Unlimited 

 Curves: Low 

 Slopes: No 
45 

Forest Park Trail 

St. Louis, MO 

Trail Profile

 Trail length: 12.1 km (7.5 mi) 

 Community context: Urban St. Louis, MO 

 Trail endpoints: Loop in Forest Park, MO 

 Trail type: Park loop 

 Part of a trail system: Connects to many trails within park 

 Managing agency: St. Louis Department of Parks, Recreation and Forestry 

Study Location Characteristics

 Study location: On the north edge of the park, along Lindell Blvd., between 

mileposts 5.25 and 5.75 (8.4 km–9.3 km), close to the 

History Museum 

 Landscape setting at study location: Open parkland, adjacent roadway 

 Surface material: Asphalt 

 Path width: 3.0 m (10.0 ft) 

 Improved shoulder: Yes; 1.2 m (4.0 ft) of dirt on one side 

 Centerline: Yes 

 Lane striping pattern: Solid centerline 

 Other treadways in the corridor: 1.2-m (4.0-ft) dirt jogging path on one side 

 Clear zone: 1.2 m (4.0 ft) 

 Landscape adjacent to clear zone: Open parkland, adjacent roadway 

 Sight distance Good 

 Curves: No 

 Slopes: No 
46 

Honeymoon Island Trail (Dunedin Causeway) 

Dunedin, FL 

Trail Profile 

 Trail length: 4.9 km (2.5 mi) 

 Community context: Suburban Tampa/St. Petersburg, FL 

 Trail endpoints: Pinellas Trail in Dunedin, FL, and 

Honeymoon Island State Park 

 Trail type: Highway sidepaths, greenway 

 Part of a trail system: Connects to the Pinellas Trail in Dunedin, FL 

 Managing agency: Florida Department of Transportation 

Study Location Characteristics 

 Study location: West of the draw bridge 

 Landscape setting at study location: Marsh, beach, adjacent roadway 

 Surface material: Asphalt 

 Path width: 2.2 m (12.0 ft) 

 Improved shoulder: No 

 Centerline: No 

 Lane striping pattern: None 

 Other treadways in the corridor: None 

 Clear zone: None on one side, 1.2–1.5 m (4.0–6.0 ft) of 

grass on the other side 

 Landscape adjacent to clear zone: Marsh, beach, guardrail, roadway 

 Sight distance Unlimited 

 Curves: Low 

 Slopes: No 
47 

Minuteman Bikeway 

Arlington, MA 

Trail Profile

 Trail length: 16.9 km (10.5 mi) 

 Community context: Suburban Boston, MA 

 Trail endpoints: Town of Bedford, MA, and Alewife "T" Station 

in Cambridge, MA 

 Trail type: Rail-trail 

 Part of a trail system: Connects to Alewife Linear Park and other trails 

 Managing agency: Town of Arlington, MA 

Study Location Characteristics

 Study location: Mile marker 7.5 (12.1 km) in Arlington, MA, 

near the Bike Shop 

 Landscape setting at study location: Wooded railroad corridor 

 Surface material: Asphalt 

 Path width: 3.7 m (12.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Dashed centerline; dashes are each 1.8 m (6.0 ft) 

long and 4.3 m (14.0 ft) apart 

 Other treadways in the corridor: None 

 Clear zone: 0.6–1.4 m (2.0–4.0 ft) 

 Landscape adjacent to clear zone: Wooded railroad corridor 

 Sight distance Okay 

 Curves: No 

 Slopes: No 
48 

Charles River Bike Path (Dr. Paul Dudley White Bike Path) 

Boston, MA 

Trail Profile

 Trail length: 29.0 km (18.0 mi) 

 Community context: Urban Boston, MA 

 Trail endpoints: O'Brien Bridge in Boston, MA, and Watertown, 

MA 

 Trail type: Linear riverside greenway 

 Part of a trail system: Circles the tidal Charles River on both 

shorelines from Science Park in Boston to 

Watertown Square 

 Managing agency: Metropolitan District Commission 

Study Location Characteristics

 Study location: South side of the Charles River, east of the 

Harvard Bridge (Massachusetts Ave.) 

 Landscape setting at study location: Narrow linear park, river, adjacent highway 

 Surface material: Asphalt 

 Path width: 2.4 m (8.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Dashed centerline; dashes are each 1.8 m (6.0 ft) 

long and 3.7 m (12.0 ft) apart 

 Other treadways in the corridor: Separate pedestrian paths are present along 

much of the trail corridor 

 Clear zone: None 

 Landscape adjacent to clear zone: Narrow linear park, river, adjacent highway 

 Sight distance Poor 

 Curves: Medium 

 Slopes: No 
49 

W&OD Trail 

Northern Virginia 

Trail Profile

 Trail length: 72.4 km (45.0 mi) 

 Community context: Suburban northern Virginia 

 Trail endpoints: I-395 at Shirlington in Arlington, VA, and 

Purcellville, VA 

 Trail type: Rail-trail 

 Part of a trail system: Serves as the east-west spine of a system of 

trails in northern Virginia 

 Managing agency: Northern Virginia Regional Park Authority 

Study Location Characteristics

 Study location: Vienna, VA 

 Landscape setting at study location: Narrow linear park 

 Surface material: Asphalt 

 Path width: 3.0 m (10.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Solid 

 Other treadways in the corridor: None 

 Clear zone: Unlimited 

 Landscape adjacent to clear zone: Narrow linear park 

 Sight distance Excellent 

 Curves: Gentle 

 Slopes: None
50 

Capital Crescent Trail 

Washington, DC 

Trail Profile

 Trail length: 14.4 km (12.0 mi) 

 Community context: Urban Washington, DC 

 Trail endpoints: Silver Spring, MD and Georgetown in 

Washington, DC 

 Trail Type: Rail-trail 

 Part of a trail system: Connects to the Rock Creek Park Trail and C&O 

Canal Towpath at the south end 

 Managing agency: Maryland National Capital Park and Planning 

Commission and the U.S. National Park Service 

(DC) 

Study Location Characteristics

 Study location: Between K St. and Fletcher's Boathouse at the 

southern end of the trail in DC 

 Landscape setting at study location: Wooded railroad corridor 

 Surface material: Asphalt 

 Path width: 3.0 m (10.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Dashed centerline 

 Other treadways in the corridor: C&O Canal Towpath parallels this section of 

trail 

 Clear zone: 0.6–1.2 m (2.0–4.0 ft) 

 Landscape adjacent to clear zone: Wooded railroad corridor 

 Sight distance No 

 Curves: Unlimited 

 Slopes: No 
51 

Grant's Trail 

St. Louis County, MO 

Trail Profile

 Trail length: 10.9 km (8.0 mi) 

 Community context: Suburban southwest St. Louis, MO 

 Trail endpoints: I–55 at Hoffmeister in Orlando Gardens, MO, 

and Highway 44 in Kirkwood, MO 

 Trail Type: Rail-trail 

 Part of a trail system: No 

 Managing agency: St. Louis County Department of Parks and 

Recreation 

Study Location Characteristics

 Study location: Near trail crossing of Union Road 

 Landscape setting at study location: Wooded railroad corridor, suburban homes 

 Surface material: Asphalt 

 Path width: 3.7 m (12.0 ft) 

 Improved shoulder: No 

 Centerline: Yes 

 Lane striping pattern: Solid yellow stripe 

 Other treadways in the corridor: None 

 Clear zone: 0.6–1.2 m (2.0–4.0 ft) 

 Landscape adjacent to clear zone: Wooded railroad corridor, suburban homes 

 Sight distance Good 

 Curves: Gentle 

 Slopes: None
52 

Pinellas Trail 

Dunedin, FL 

Trail Profile

 Trail length: 75.7 km (47.0 mi) 

 Community context: Suburban Tampa/St. Petersburg, FL 

 Trail endpoints: Tarpon Springs, FL, and St. Petersburg, FL 

 Trail type: Rail-trail 

 Part of a trail system: Serves as the north-south spine for a system of 

trails and on-street bikeways in Pinellas County, 

FL 

 Managing agency: Pinellas County Park Department 

Study Location Characteristics

 Study location: North of Curlew Road in Dunedin, FL 

 Landscape setting at study location: Narrow linear park 

 Surface material: Asphalt 

 Path width: 4.6 m (15.0 ft) 

 Improved shoulder: None 

 Centerline: Yes 

 Lane striping pattern: Solid white stripe divides bicycle/skate path (3.0 

m (10.0 ft)) from pedestrian path (1.5 m (5.0 ft)), 

which is periodically marked with a white 

pedestrian symbol 

 Other treadways in the corridor: Along some segments of the trail, the bicycle 

and pedestrian paths are separated by a grass 

buffer 

 Clear zone: 1.8–3.0 m (6.0–10.0 ft) 

 Landscape adjacent to clear zone: Narrow Linear Park 

 Sight distance Unlimited 

 Curves: None 

 Slopes: None
53 

White Creek Trail 

Dallas, TX 

Trail Profile

 Trail length: 12.1 km (7.5 mi) 

 Community context: Suburban northern Dallas, TX 

 Trail endpoints: Valley View Park (Hilcrest Road) in north 

Dallas, TX, and White Rock Lake Park in 

northeast Dallas, TX 

 Trail Type: Linear streamside greenway 

 Part of a trail system: Connects to the White Rock Lake Trail on the 

south end 

 Managing agency: Dallas Department of Parks and Recreation 

Study Location Characteristics

 Study location: North of the Fair Oaks Tennis Center, on both 

sides of the Walnut Hill Lane overpass 

 Landscape setting at study location: Open parkland, stream 

 Surface material: Asphalt 

 Path width: 2.4 m (8.0 ft) 

 Improved shoulder: No 

 Centerline: No 

 Other treadways in the corridor: None 

 Clear zone: 9.2–22.9 m (30.0–75.0 ft) of grass with sparse 

tree cover. 

 Landscape adjacent to clear zone: Open parkland, stream 

 Sight distance: Unlimited 

 Curves: None 

 Slopes: None

 55

APPENDIX B. FACTORS USED IN THE LOS MODEL 

Table 11 provides a summary list of the key factors used in the Shared-Use Path LOS model. It also 

provides the shorthand name for each factor and a general description of how it functions in the model. 

Table 11. Factors used in the shared-use path LOS model. 

Factors found to affect 

bicyclists’ LOS 

Shorthand 

name 

How the factor functions in the model 

Overall user volume One-way volume 

per hour 

Used in the calculations of meetings, active 

passes, and delayed passes 

Peak-hour factor PHF 

Accounts for flow peaking that was found to be 

common within hourly counts. Boosts base 

volume by 17.6 percent 

Percentage of volume 

assigned to each of the 

five user types 

Mode split Used in the calculations of active passes, number 

of meetings, and number of delayed passes 

User speed 

Speed: average 

and standard 

deviation 

Used in the calculations of meetings, active 

passes, and probability of delayed passes 

Passing users traveling in 

the same direction Active pass Multiplied by 10 and added to meetings to create 

total events 

Test bicyclist speed Test bicyclist 

speed 

Used in the calculations of meetings, active 

passes, and probability of delayed passes 

Meeting users traveling 

in opposite direction Meetings Added to 10 x active passes to create total events 

Meetings and active 

passes 

Events Total number of events and width determine 

LOS; calibrated to user perception survey grades 

Path width Width 

Limits or enables passes, determines impact of 

potential blockages, defines operational 

characteristics, and is calibrated to user 

perception survey grades 

Other users block active 

passing event Delayed pass 

Total number of delayed passes, from 0 to 180, 

correlates to a reduction of baseline LOS score of 

0 to 1.5 

Presence of a striped 

centerline Centerline Correlates to a .28 reduction in baseline LOS score 

 57

APPENDIX C. LOS LOOK-UP TABLES 

Table 12. Shared-use path level of service look-up table, typical mode split. 

 Trail Width (feet) 

 8 10 12 14 16 18 20 

25 B B B B A A A 

50 D C B B A A A 

75 D C B B B A A 

100 D D B B B A A 

150 E D C C B B B 

200 F E D C C B B 

250 F F D D C C C 

300 F F E E D C C 

400 F F F F E E E 

500 F F F F F F F 

600 F F F F F F F 

800 F F F F F F F 

Trail Volume (One Direction per Hour) 

1000 F F F F F F F 

1 ft = 0.3 m 

Table Assumptions 

Mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists. 

An equal number of trail users travel in each direction (the model uses a 50%/50% directional split). 

Trail volume represents the actual number of users counted in the field (the model adjusts this volume 

based on a peak hour factor of 0.85). 

Trail has a centerline. 
 58

Table 13. Shared-use path level of service look-up table, high bicycle mode split. 

 Trail Width (feet) 

 8 10 12 14 16 18 20 

25 A A A A A A A 

50 B B B B A A A 

75 B B B B A A A 

100 D C B B A A A 

150 D C B B B A A 

200 E D C B B B A 

250 E D C C B B B 

300 F E C C B B B 

400 F F D D C C B 

500 F F E E C C C 

600 F F F F D D D 

800 F F F F E E E 

Trail Volume (One Direction per Hour) 

1000 F F F F F F F 

1 ft = 0.3 m 

Table Assumptions 

Mode split is 75% adult bicyclists, 7.5% pedestrians, 7.5% runners, 5% in-line skaters, and 5% child bicyclists. 

An equal number of trail users travel in each direction (the model uses a 50%/50% directional split). 

Trail volume represents the actual number of users counted in the field (the model adjusts this volume based on a 

peak hour factor of 0.85). 

Trail has a centerline. 
 59

Table 14. Shared-use path level of service look-up table, high pedestrian mode split. 

 Trail Width (feet) 

 8 10 12 14 16 18 20 

25 B B B B A A A 

50 D C B B B A A 

75 E D C B B B B 

100 F E C C C B B 

150 F F E D D D C 

200 F F F F E E E 

250 F F F F F F F 

300 F F F F F F F 

400 F F F F F F F 

500 F F F F F F F 

600 F F F F F F F 

800 F F F F F F F 

Trail Volume (One Direction per Hour) 

1000 F F F F F F F 

1 ft = 0.3 m 

Table Assumptions 

Mode split is 25% adult bicyclists, 50% pedestrians, 15% runners, 7.5% in-line skaters, and 2.5% child bicyclists. 

An equal number of trail users travel in each direction (the model uses a 50%/50% directional split). 

Trail volume represents the actual number of users counted in the field (the model adjusts this volume based on a 

peak hour factor of 0.85). 

Trail has a centerline. 
 60

Table 15. Shared-use path service volume look-up table, typical mode split. 

 Trail Width (feet) 

 8 10 12 14 16 18 20 

A 24 24 24 24 70 102 125 

B 49 49 110 147 191 213 229 

C 49 97 198 226 282 300 315 

D 109 155 267 290 362 379 392 

Level of Service 

E 167 212 328 349 436 452 464 

F N/A N/A N/A N/A N/A N/A N/A 

Table shows maximum trail volume (one direction per hour) in each LOS category 

1 ft = 0.3 m 

Table Assumptions 

Mode split is 55% adult bicyclists, 20% pedestrians, 10% runners, 10% in-line skaters, and 5% child bicyclists. 

An equal number of trail users travel in each direction (the model uses a 50%/50% directional split). 

Trail volume represents the actual number of users counted in the field (the model adjusts this volume based on a 

peak hour factor of 0.85). 

Trail has a centerline. 
 61

Table 16. Shared-use path service volume look-up table, high bicycle mode split. 

 Trail Width (feet) 

 8 10 12 14 16 18 20 

A 40 40 40 40 123 182 224 

B 81 81 185 246 348 388 419 

C 81 162 330 376 519 554 581 

D 184 267 446 487 671 703 728 

Level of Service 

E 289 373 551 590 812 842 866 

F N/A N/A N/A N/A N/A N/A N/A 

Table shows maximum trail volume (one direction per hour) in each LOS category 

1 ft = 0.3 m 

Table Assumptions 

Mode split is 75% adult bicyclists, 7.5% pedestrians, 7.5% runners, 5% in-line skaters, and 5% child bicyclists. 

An equal number of trail users travel in each direction (the model uses a 50%/50% directional split). 

Trail volume represents the actual number of users counted in the field (the model adjusts this volume based on a 

peak hour factor of 0.85). 

Trail has a centerline. 
 62

Table 17. Shared-use path service volume look-up table, high pedestrian mode split. 

 Trail Width (feet) 

 8 10 12 14 16 18 20 

A 13 13 13 13 35 51 62 

B 26 26 57 77 95 105 114 

C 26 52 105 120 140 149 156 

D 58 82 143 156 179 187 194 

Level of Service 

E 87 110 177 189 215 223 229 

F N/A N/A N/A N/A N/A N/A N/A 

Table shows maximum trail volume (one direction per hour) in each LOS category 

1 ft = 0.3 m 

Table Assumptions 

Mode split is 25% adult bicyclists, 50% pedestrians, 15% runners, 7.5% in-line skaters, and 2.5% child bicyclists. 

An equal number of trail users travel in each direction (the model uses a 50%/50% directional split). 

Trail volume represents the actual number of users counted in the field (the model adjusts this volume based on a 

peak hour factor of 0.85). 

Trail has a centerline. 
 63

REFERENCES 

1. Cordell, K., principal author, Outdoor Recreation for the 21st. Century: A Report to the Nation: 

The National Survey on Recreation and the Environment, Venture Publishing, State College, PA, 

2003. 

2. Guide for the Development of Bicycle Facilities, American Association of State Highway and 

Transportation Officials, Washington, DC, 1999. 

3. Rouphail, N., J. Hummer, J. Milazzo II, and P. Allen, Capacity Analysis of Pedestrian and 

Bicycle Facilities: Recommended Procedures for the “Bicycles” Chapter of the Highway 

Capacity Manual, FHWA-RD-98-108, Federal Highway Administration, McLean, VA, 2000, 

available online at http://www.fhwa.dot.gov/tfhrc/safety/pubs/98-108/contents.htm#contents. 

4. Botma, H., and H. Papendrecht, “Traffic Operations of Bicycle Traffic,” Transportation Research 

Record 1320, Transportation Research Board, Washington, DC, pp. 65–72, 1991. 

5. Harkey, D., D. Reinfurt, M. Knuiman, J. Stewart, and A. Sorton, The Bicycle Compatibility 

Index: A Level of Service Concept, Final Report, FHWA-RD-98-072, Federal Highway 

Administration, Washington, DC, 1998. 

6. Landis, B.W., V.R. Vattikuti, and M.T. Brannick, “Real-Time Human Perceptions: Toward a 

Bicycle Level of Service,” Transportation Research Record 1578, Transportation Research 

Board, 1997. 

7. Evaluation of Safety, Design, and Operation of Shared-Use Paths—Final Report, FHWA-HRT05-137, Federal Highway Administration, Washington, DC, 2006. 

8. Highway Capacity Manual, Transportation Research Board, Washington, DC, 2000.