An Analysis of Factors Contributing to 

“Walking Along Roadway” Crashes:

Research Study and Guidelines

for Sidewalks and Walkways

REPORT NO. FHWA-RD-01-101

 

 February 2002

U.S. Department of Transportation

Federal Highway Administration

Research and Development

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296
FOREWORD

The Federal Highway Administration’s (FHWA) Pedestrian and Bicycle Safety Research Program’s

overall goal is to increase pedestrian and bicycle safety and mobility. From better crosswalks,

sidewalks, and pedestrian technologies to expanding public educational and safety programs, the

FHWA’s Pedestrian and Bicycle Safety Research Program strives to pave the way for a more walkable

future.

The following document summarizes the results of a study that examined the safety impacts of having

sidewalks and walkways along roadways. The document also provides guidelines and

recommendations for providing such facilities. The sidewalk study was part of a large FHWA study

“Evaluation of Pedestrian Facilities” that has produced a number of other documents regarding the safety

of pedestrian crossings and the effectiveness of innovative engineering treatments on pedestrian safety. It

is hoped that readers also will read the reports documenting the results of the related pedestrian safety

studies.

The results of this research will be useful to transportation engineers, planners, and safety professionals

who are involved in improving pedestrian safety and mobility. 

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 United States Government assumes no liability for its contents or use

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

The United States Government does not endorse products or manufacturers. Trade or manufacturers’

names appear herein only because they are considered essential to the object of this document.
Technical Report Documentation Page

1. Report No.

FHWA-RD-01-101

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

4. Title and Subtitle

AN ANALYSIS OF FACTORS CONTRIBUTING TO

“WALKING ALONG ROADWAY” CRASHES: RESEARCH STUDY

AND GUIDELINES FOR SIDEWALKS AND WALKWAYS

5. Report Date

 

6. Performing Organization Code

7. Author(s): Patrick J. McMahon, Charles V. Zegeer, Chandler Duncan,

Richard L. Knoblauch, J. Richard Stewart, and Asad J. Khattak 

8. Performing Organization Report No.

9. Performing Organization Name and Address

University of North Carolina

Highway Safety Research Center

Chapel Hill, NC 27599-3430

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

 DTFH61-92-C-00138 

12. Sponsoring Agency Name and Address

Office of Safety Research and Development

Federal Highway Administration 

6300 Georgetown Pike

McLean, VA 22101-2296

13. Type of Report and Period Covered

 Final Report

 1998-2001

14. Sponsoring Agency Code

15. Supplementary Notes

Contracting Officer’s Technical Representative (COTRs): Carol Tan Esse and Ann Do, HRDS

16. Abstract

There are a variety of factors widely acknowledged to have an impact on the risk of pedestrian/motor vehicle

crashes. The factors that have been most extensively researched are the geometric characteristics of the

road, including the presence of sidewalks. However, in relevant epidemiological research, factors related to

demographics and neighborhood characteristics have been alluded to, but not sufficiently researched. This

study uses a case-control methodology and applies conditional and binary logistic models to determine the

effects of cross-sectional roadway design attributes and socioeconomic and other census block group data

on the likelihood that a site is a crash site. A total of 47 crash sites and 94 comparison sites are analyzed. 

Physical design factors found to be associated with a significantly higher likelihood of being a crash site are

higher traffic volume, higher speed limit, the lack of wide grassy walkable areas, and the absence of

sidewalks. When these roadway factors are controlled for, non-geometric factors associated with a

significantly higher likelihood of being a crash site are high levels of unemployment, older housing stock,

lower proportions of families within households, and more single-parent households. This information

suggests that some neighborhoods, due to increased exposure or specific types of exposure, may be

especially appropriate sites for pedestrian safety measures such as sidewalks, lower speed roadway

designs, and the addition of wide grassy shoulders.

This report also documents the results of a behavioral evaluation of a new sidewalk in SeaTac, Washington

(Appendix A). Recommended guidelines and priorities for sidewalks and walkways are given in Appendix B.

17. Key Words 

Pedestrian crashes, sidewalks, guidelines.

18. Distribution Statement

No restrictions. This document is available to the

public through the National Technical Information

Service, Springfield, VA 22161.

19. Security Classification (of this report)

Unclassified

20. Security Classification (of this page)

Unclassified

21. No. of Pages

47

22. Price

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

TABLE OF CONTENTS

 Page

INTRODUCTION ............................................................. 1

LITERATURE REVIEW ......................................................... 1

OBJECTIVE AND SCOPE ...................................................... 2

METHODOLOGY ............................................................. 3

ANALYSIS OF THE ROADWAY FACTORS USING CONDITIONAL LOGISTIC

 ANALYSIS ................................................................ 4

ANALYSIS OF THE ROADWAY AND DEMOGRAPHIC FACTORS USING THE 

 BINARY LOGISTIC MODEL .................................................. 8

Percentage of Single Parents ................................................ 10

Percentage of Housing Stock Built After 1980 .................................. 10

Percentage of Families .................................................... 12

Unemployment .......................................................... 12

Pedestrian and Vehicle Volumes ............................................. 13

Grassy and Other Unpaved Shoulder Spaces ................................... 13

CONCLUSION .............................................................. 13

REFERENCES ............................................................... 14

APPENDIX A. INTERNATIONAL BOULEVARD SIDEWALK IMPACT STUDY: 

SeaTac, WASHINGTON ................................................ 17

APPENDIX B. RECOMMENDED PRIORITIES AND GUIDELINES FOR SIDEWALKS AND

WALKWAYS ......................................................... 27
iv

LIST OF FIGURES

Page

Figure 1. Wake County pedestrian “walking along roadway” crash locations 

 (1993-1996), non-crash faraway comparison sites, and single-parent 

 household percentages .................................................. 9

LIST OF TABLES

Page

Table 1. Frequency of speed limit, paved sidewalk, and wide paved shoulder 

by site type .......................................................... 5

Table 2. Motor vehicle traffic volume distribution by site type (hourly vehicle

volume for the outside lanes at the hour the crash took place) ..................... 6

Table 3. SAS PROC PHREG procedure: Best subsets selected by score criterion ........... 7

Table 4. Results for three variable models .......................................... 7

Table 5. Effects of marginal changes in independent variables in the binary logistic 

model ............................................................. 11
1

INTRODUCTION

The goal of a transportation system is to provide safe and efficient mobility and access to different

modes of travel to a wide variety of travelers with diverse needs. Walking is the most basic form of

transportation, and it is important for transportation officials to provide facilities that enhance safe

movement for pedestrians along roads and streets. An individual’s transportation needs, and his or her

ability to meet them, are likely to vary not only according to the physical roadway environment, but also

according to their socioeconomic situations and the proximity of potential attractors. Neighborhoods

have their own specific patterns of transportation and travelers within those neighborhoods may be

subject to different risks than encountered in other areas.

The purpose of this paper is to identify the types of risks to pedestrians who are walking along a

roadway and the reasons for those risks. Factors examined in this study include both roadway factors

and neighborhood factors. The sampling methodology matches crash sites where pedestrians were

struck walking along a roadway to comparison sites of similar zoning, parcel size, and level of

development, much like the matching done in a case-control study. Such roadway factors as vehicle

volume, pedestrian volume, presence of sidewalk, shoulder width, and type of roadside are included in

the analysis. Census data from the U.S. Census block group in which each site was located was

attributed to that crash site in order to analyze the impact of socioeconomic and other neighborhood

factors (e.g., unemployment level, age of housing, and number of parents in the household).

LITERATURE REVIEW

Hunter et al. found “walking along roadway” crashes to comprise 7.9 percent (400 of 5,073) of all

pedestrian/motor vehicle crashes of a sample from six States (1). Of the 400 crashes, they found that

69 percent involved pedestrians walking with traffic and 21 percent involved pedestrians walking

against traffic. Overrepresented variables of these 400 “walking along roadway” crashes included:

! Pedestrians 15 to 44 years of age.

! Alcohol involvement by the pedestrian and/or driver.

! Rural, two-lane roads.

! Dark conditions with no lights.

! Interstate and county roads.

A number of studies have applied case-control methods to questions of pedestrian safety. For example,

Carlin et al. used a case-control method to examine the effects of the behavior and attributes of children

in determining their propensity to be involved in bicycle crashes (2). One of the findings of this study

was a disproportionate number of injuries among children in the lowest income category.

A limited number of studies have investigated roadway factors associated with “walking along

roadway” pedestrian/motor vehicle crashes. In a 1996 study by Knoblauch et al. involving an analysis

of pedestrian/motor vehicle crashes and exposure under various roadway situations, locations with no

sidewalks were more than twice as likely to have pedestrian/motor vehicle crashes than sites where
2

sidewalks existed. The presence of a sidewalk was found to have a particularly large safety benefit in

residential and mixed residential areas. However, sidewalks had no effect on pedestrian/motor vehicle

crash experiences in commercial areas (3).

A wide variety of studies have acknowledged the increased risk of pedestrian injuries in some

socioeconomic groups, with a focus on children and youth. These studies have generally shown that

children of minorities and low-income families tend to be disproportionately represented in groups

especially prone to pedestrian/motor vehicle crashes and injuries. For example, Roberts recognized a

connection between economic and ethnic differences, concentrating on the increased “exposure to risk”

of children of single parents, often in lower income brackets, with regard to supervision of playing near

roads and walking to school (4-5). King found that neighborhoods with high pedestrian injuries in the

West Midlands (U.K.) had high proportions of immigrant heads of households (6). Epperson noted

that the economic status of neighborhood residents plays an important role in the prediction of areas

with high bicycle crash rates (7). He theorized that this was due to increased dependence on bicycles

as a mode of transportation. It may be concluded from these studies that the overrepresentation of

crash risk among some lower income people and minorities is probably the result of different travel

patterns, proximity to dangerous streets, less supervision of children at play near streets, and/or the

lower likelihood of large fenced-in yards, compared to higher income neighborhoods, etc. 

Some of these researchers have used methods similar to those in this paper. Christie used logistic

regression to determine the socioeconomic and environmental factors that increased the likelihood of

individual children to have been involved in a crash (8). Bagley, on the other hand, analyzed the

likelihood of neighborhoods to be sites of crashes given socioeconomic and crime data (9). He found

“general” crime, the percentage of subsidized housing, population density, percentage unemployed, and

low birth weights to be correlated with pedestrian crashes, and the percentage of park space to be

negatively correlated with crashes (i.e., more park space correlates with a lower risk of pedestrian

crashes) (10). Finally, Braddock used geographic information systems (GIS) to map out the

pedestrian/motor vehicle crashes involving youth and found a non-uniform distribution, but he did not

appear to have looked at the socioeconomic characteristics of these neighborhoods (11).

OBJECTIVE AND SCOPE

The first objective of this paper was to identify roadway design factors and neighborhood

socioeconomic factors that distinguish “walking along roadway” crash sites from other matched sites in

the same neighborhood and also in faraway neighborhoods. The second objective was to suggest

measures that are likely to reduce the occurrence of such crashes.

Wake County, North Carolina, was selected as the study area because it contains a mix of urban,

suburban, and rural conditions, and 4 years of crash data were easily available for research purposes. 

Sites could be visited and geometric data obtained for the crash and faraway comparison sites. Finally,

the number of sites—141, including the crash site and both nearby and faraway comparison sites—was

adequate to conduct multivariate analysis with minimal difficulties.
3

The 47 “walking along roadway” crashes in this 4-year sample (1993-1996) constituted 6.61 percent

of the 711 pedestrian/motor vehicle crashes in Wake County during the same period. Based upon the

crash reports, it was found that roughly 77 percent of the crashes involved pedestrians walking with

traffic and 23 percent involved pedestrians walking against traffic. A small proportion of the

pedestrians walking with traffic were hit by oncoming traffic and a small proportion of the pedestrians

walking against traffic were hit from behind. These trends compare closely with the 1996 study by

Hunter et al. (1), as discussed earlier.

METHODOLOGY

This paper uses the case-control method often used in epidemiology. The study analyzes variation

between sites, not individuals. For this reason, the case sites were matched with nearby (same

neighborhood) and faraway (other side of town) comparison sites. The comparison sites were chosen

on the basis of current land use. A tax assessors’ map from the Wake County Planning Department

was used to match crash sites to nearby and more distant comparison sites.

Crash sites were pinpointed on the color-coded zoning map. Then, for each case site, comparison

areas of the county, with the same type of zoning, covering about the same amount of area, with the

same sized parcels as the crash site—but with no crashes—were identified. From this suitable

comparative area of the county, a segment of roadway with the same functional class and number of

lanes as the crash segment was chosen without regard to vehicle volume, sidewalk presence, or any

other variables for which data were collected. The entire process was done prior to visiting the sites. 

Comparison site selection was done in this manner to avoid bias in the selection.

The issue of exposure was addressed in the analysis by including vehicle and pedestrian counts as

independent variables in the models. Hence, the analysis controls for exposure without matching sites

by traffic counts. Vehicle volumes listed in this paper refer to the number of vehicles counted in the

outside lanes at the sites (i.e., the lanes closest to pedestrians walking along the roadway) over the

course of 1 hour. These volume measurements, like the other site measurements, were taken at

approximately the same time of day as the crash occurred. However, no counts were taken after

midnight or before 6:00 a.m.

Because of the low frequency of “walking along roadway” crashes, it would take many years of

observing a very large number of links before enough crashes could be observed for use in some types

of experimental designs (e.g., before/after with a cohort analysis). For this reason, this study begins

with known crash sites, then identifies matched nearby and faraway comparison sites. While a segment

was defined as an unintersected stretch of roadway, specific measurements of segment lengths were not

taken. However, because crash and comparison segments were in areas with similar levels of

development and on the same functional class of roadway, they were of comparable length in all cases. 

These sampling strategies are appropriate, given the conceptual framework of the study and the policy

questions being addressed.

This sampling method yields a set of three sites for each of the 47 crash sites (all of the “walking along

roadway” crashes in Wake County from 1993 through 1996), consisting of (1) the crash site, (2) a
4

nearby comparison site, and (3) a distant comparison site. Hence, a total of 141 sites were observed. 

Each crash site was the location of a single pedestrian/motor vehicle crash during the period studied

(although two crashes involved two pedestrians each). Data collectors visited these matched sites

generally during the same hour that the crash occurred. For example, if a crash occurred at 6:30 a.m.,

data collectors visited the crash and faraway comparison sites from 6:00 a.m. to 7:00 a.m. on a given

morning, collecting pedestrian and vehicular volumes and making detailed measurements of crosssectional design attributes.

Two different types of modeling analyses were conducted to quantify roadway and neighborhood

effects on “walking along roadway” pedestrian/motor vehicle crashes. The first of these was a matched

case-control analysis carried out using SAS PROC PHREG (explained below) that examined the

geometric roadway data at all three types of sites (i.e., crash sites, nearby comparison sites, and

faraway comparison sites), while the other used Statistical Packages for Social Sciences and a binary

logistic regression and addressed both geometric and neighborhood demographic factors at the crash

site and the distant comparison site.

SAS PROC PHREG is a procedure for survival analysis based on the Cox proportional hazards

model. It has been concluded that a matched conditional logistic model has a likelihood function that is

a special case of a proportional hazards model. Details can be found in Stokes et al. (11). Another

reference is SAS/STAT Software Changes and Enhancements through Release 6.11 (12). SPSS for

Windows, Release 7.5.1, was used to estimate the parameters of the binary logistic model.

Several of these variables differ considerably between the crash sites and faraway comparison sites. 

On the other hand, both the demographic variables and the roadway characteristics would have been

expected to differ only slightly between the crash sites and non-crash nearby comparison sites (i.e.,

since non-crash nearby comparison sites were typically selected on a nearby street crossing the street

of the crash site).

It was expected that the nearby locations would have been exposed to much the same population of

drivers and pedestrians as the crash sites and, hence, would, to some extent, control for these factors. 

Yet, there was concern that street design within the same neighborhood might be so uniform that it

would tend to control out the factors of interest (e.g., sidewalk present or absent). The more distant

locations would not be expected to be exposed to the same distributions of motorists and pedestrians,

but the matching might be expected to yield some degree of similarity. These sites should also add

variability to the observed roadway designs. Therefore, the selection of both a nearby and faraway

comparison site was considered desirable for each crash site. 

ANALYSIS OF THE ROADWAY FACTORS 

USING CONDITIONAL LOGISTIC ANALYSIS

Among the data elements collected at each location, the following were the key variables used in the

statistical analysis:
5

! Speed limit.

! Sidewalk (present or absent).

! Paved shoulder width.

! Gutter pan width.

! Pedestrian volume.

! Traffic volume in the outside lanes.

! Unpaved walkable space.

A four-way tabulation is given in Table 1 of speed limit by site type, by sidewalk presence, and by

presence or absence of a paved shoulder 0.76 m (2.5 ft) in width or wider. The crash sites differed

from the comparisons for a few of the roadway variables, namely, speed limit, 

sidewalk presence, and traffic volume. Table 1 shows that these differences are primarily

Table 1. Frequency of speed limit, paved sidewalk, and wide paved shoulder by site type.

Site Type Paved

Sidewalk

 Paved 

Shoulder*

 Speed Limit in km/h (mi/h)

 

Total

32 

(20)

 40

(25)

 48

(30)

 56

(35)

 72

(45)

 89

(55)

Crash Site No

No

Yes

Yes

No

Yes

No

Yes

1

0

0

0

 2

 0

 0

 0

0

0

0

0

 11

 2

 4

 0

 14

 4

 0

 0

 8

 1

 0

 0

 36

 7

 4

 0

 Far

Comparison

No

No

Yes

Yes

No

Yes

No

Yes

2

0

0

0

13

 0

 5

 0

0

0

1

0

 5

 0

 6

 0

8

2

3

0

1

1

0

0

29

 3

15

 0

 Near

Comparison

No

No

Yes

Yes

No

Yes

No

Yes

1

0

0

0

 6

 0

 2

 0

0

0

0

0

 11

 0

 4

 1

 15

 2

 0

 1

3

1

0

0

 36

 3

 6

 2

Total 4 28 1 44 49 15 141

*Paved shoulder width $0.76 m (2.5 ft)

between the crash sites and the more distant comparison sites. The distribution of observed traffic

volumes for the three site types is presented in Table 2. Observed pedestrian volumes appeared to

differ very little across site types, with at least one pedestrian observed about 50 percent of the time at

each of the three site types. The 90th percentiles for observed hourly pedestrian volumes were 10, 8,

and 8 for crash, far, and near sites, respectively. 
6

Table 2. Motor vehicle traffic volume distribution by site type (hourly 

vehicle volume for the outside lanes at the hour the crash took place).

Percentiles

Site Type

Crash

Site

Far

Comparison

Near

Comparison

10th

25th

50th

75th

90th

32

85

174

502

942

13

22

66

241

625

14

26

103

285

644

With respect to other characteristics of the data, paved shoulders (of any width) were present at 61.7

percent of the crash sites, 29.8 percent of the far comparison sites, and 57.4 percent of the near

comparison sites. There were no sidewalks on either side of the street at 80.9 percent of the sites

visited, with no sidewalks at 91.5 percent of the crash sites and 75.5 percent of the non-crash

comparison sites. In general, the data indicated that the crash locations tended to be more rural, have

higher speed limits and traffic volumes, be more likely to have paved shoulders, and be less likely to

have sidewalks when compared to the non-crash comparison sites.

Statistical analyses were carried out by including the variables listed above in a series of conditional

logistic models. Conditional logistic analysis is a standard method of analysis for matched case-control

studies (12). In this setting, each observation consists of a response variable indicating a case (crash

location) or comparison and values of each of the independent variables. The procedure maximizes the

likelihood that a case is correctly classified as a function of the independent variables (e.g., roadway

variables), given the condition that exactly one of each matched triplet is a case. Table 3 contains

results from SAS PROC PHREG obtained by using a best subset selection criterion for selecting best

subsets of seven independent variables input to the procedure.

The results in Table 3 show that speed limit is clearly the dominant variable for discriminating between

crash and comparison sites. Beyond this, the models are not unique in the sense that different

combinations of variables yield similar values of the score statistic, a goodness-of-fit measurement

having an approximate P

2

 distribution with degrees of freedom equal to the number of included

variables. This is not surprising, given the correlated nature of the variables. Table 4 shows the

parameter estimates and associated statistics for the best three-variable model, those being speed limit,

presence of sidewalk, and traffic volume.
7

This model shows speed limit to be highly significant, while presence of sidewalks and traffic volume are

significant at levels just below and just above the 0.05 level. While speed limits are

not perfect measures of roadway speeds, it was believed that this adequately approximates the

Table 3. SAS PROC PHREG procedure: Best subsets selected by score criterion.

No. of Variables Score Value Variables Included

1

1

15.39

11.11

Speed limit

Gutter pan width

2

2

19.18

19.17

Speed limit, gutter pan width

Speed limit, paved sidewalk

3

3

22.25

21.51

Speed limit, paved sidewalk, traffic 

 volume

Speed limit, paved sidewalk, gutter pan 

 width

4

4

23.59

22.61

Speed limit, traffic volume, gutter pan

 width

Speed limit, unpaved walkable space,

 gutter pan width

Table 4. Results for three variable models.

Variable

Coefficient

 (Estimate) 

Standard

 Error P

2 p-Value Risk Ratio

95%

Confidence

Intervals

Speed Limit 0.1094 0.0381 8.22 0.0041 1.116 (1.035, 1.202)

Paved

Sidewalk

-2.1346 1.077 3.93 0.0474 0.118 (0.014, 0.976)

Traffic

Volume

0.0019 0.0010 3.69 0.0549 1.002 (1.000, 1.004)

speeds of vehicles on these roadways for the purpose of this analysis. When more variables are added

to the model, significance levels of some variables increase to about 0.10 or higher. Table 4 also

contains a column heading “Risk Ratio.”
8

For the variable “presence of sidewalk,” the Risk Ratio = 0.118. This means that given the data at

hand, when speed limit and traffic volume are taken into account, the likelihood of a site with a paved

sidewalk being a crash site is 88.2 percent lower than a site without a sidewalk. This should not be

interpreted to mean that installing sidewalks would necessarily reduce the likelihood of pedestrian/motor

vehicle crashes by 88.2 percent in all situations. However, the presence of a sidewalk clearly has a

strong beneficial effect of reducing the risk of a “walking along roadway” pedestrian/motor vehicle

crash. 

Risk ratios for speed limit and traffic volume are also shown in Table 4. As expected, increases in

traffic volume and speed limit are associated with a greater likelihood of a location being a crash site. 

The results in Table 4 also show that by increasing the traffic volume by 1 unit (e.g., from 300 to 301

vehicles per hour), the risk ratio is 1.002. This means that the probability that the location is a crash site

increases by 0.2 percent. For an increase in vehicle volume of 100 (e.g., from 300 to 400), there

would be an increase in the probability that the location is a crash site by a factor of (1.002)100 = 1.22

(a 22 percent increase). The speed limit risk ratio was 1.116. This means that each 1.6-km/h (1.0-

mi/h) increase in speed limit increases the likelihood of a location being a crash site by a factor of

1.116. An 8-km/h (5-mi/h) increase in speed limit increases the likelihood by (1.116)5 = 1.73, while a

16.1-km/h (10-mi/h) increase yields a factor of (1.116)10 = 3.0.

With regard to other potential roadway variables, data were collected for on-street parking and for

street lighting. None of the sites sampled contained bicycle lanes and data were not collected for

sidewalk buffer strips. Given the sample size, the diversity of urban and rural sites, and the minimal

number of nighttime crashes, on-street parking and street lighting did not prove to be significant in any

of the final specifications of these models. This is not to suggest that these variables are not important

factors regarding the incidence of “walking along roadway” crashes, but that the sample here was not

adequate to effectively analyze these factors.

ANALYSIS OF THE ROADWAY AND DEMOGRAPHIC FACTORS

USING THE BINARY LOGISTIC MODEL

Following the collection of roadway attributes, each of these crash sites was manually entered into

ArcView for GIS plotting purposes. The sites were then linked with the roadway characteristics

mentioned above and then with the information from the 1990 U.S. Census block group within which

they were located. As the nearby comparison sites were likely to have the same Census data, and

hence no variation in the neighborhood variables, this analysis used only the crash sites and the faraway

comparison sites. This data file was then loaded into SPSS and a binary logistic regression was run. 

An illustration of the location of crash sites, non-crash faraway comparison sites, and the percentage of

single-parent households by U.S. Census block group is shown in Figure 1.

The methods used to compare the attributes of the sites include GIS maps, a binary logistic regression

model, and a table showing the mean of each variable for the crash sites and the corresponding mean

for the comparison sites. The binary logistic model was chosen because, since this analysis only looked

at the crash and faraway comparison sites, the binary logistic model accounts for the alternate
9

Figure 1. Wake County pedestrian “walking along roadway” crash locations (1993-1996), 

non-crash faraway comparison sites, and single-parent household percentages.

possibility that a site will be either a crash (1) or a comparison (0) site. This model identifies the

statistical significance and degree to which certain attributes distinguish a crash site from a comparison

site and gives the marginal effects of each relationship.

The model specification included a variety of geometric factors that were statistically significant in the

analysis discussed previously. Added to these factors were a number of variables based on Census

data that were believed to potentially correlate with crash sites and also to approximate some ways in

which specific neighborhoods may contain greater, or different, risks of “walking along roadway”

crashes for pedestrians.
10

The average median household income in the block groups of crash sites is $31,653, while it is $41,279

at non-crash, faraway comparison sites. Nearly 2.7 percent of the residents around crash sites take the

bus to work and 2.7 percent walk. At the non-crash, faraway comparison sites, less than 0.25 percent

take the bus and 1.1 percent walk. Minorities comprised 39 percent of the

block groups around crash sites, but only 15 percent of non-crash, faraway comparison sites. Just over

63 percent of the homes in crash neighborhoods were owner-occupied, while non-crash, faraway

comparison sites were nearly 76 percent owner-occupied.

Through the binary logistic regression (see Table 5), several roadway design factors and neighborhood

characteristics were found to be statistically significant. These results were very similar to the results of

the conditional logistic modeling above and confirmed that reduced crash

risk was associated with lower traffic volumes, lower vehicle speeds, and having a sidewalk present. 

The binary logistic analysis also showed that wide, unpaved shoulders reduce the risk of “walking along

roadway” crashes. However, having controlled for these geometric factors, Census variables that were

significantly correlated with crash sites were:

! Percentage of single parents with children. 

! Less than 30 percent of housing stock built after 1980. 

On the other hand, variables significantly correlated with non-crash, faraway comparison sites were:

! High percentage of families within households. 

! Extremely low levels of unemployment (less than 1.75 percent).

When reading through the results of this binary logistic regression, and specifically when looking at the

coefficients and marginal effects, it is important to keep in mind the fact that the data set used to

produce this model consisted of sites in only one North Carolina county. Therefore, the numeric values

associated with each variable should be understood to be relative and indicative of a clear pattern, but

not a definitive finding that can necessarily be generalized to all other jurisdictions. A brief discussion of

some of the neighborhood factors is given below.

Percentage of Single Parents

As mentioned in Roberts, single parents with children are likely to have less ability, given the other

demands on their time, to extensively monitor their children (4-5). Children in neighborhoods

characterized by large numbers of this household type may take part in riskier behavior without the

supervision of an adult. Thus, it was expected that the percentage of single parents might be positively

correlated with the likelihood of a location being a crash site.

The model supports this hypothesis, showing that an increase from 7 to 8 percent in the number of

single-parent households results in a 13-percent increase in the likelihood of a location being a crash

site. However, complicating this finding is the lack of a clear relationship between the ages of

pedestrians struck walking along the roadway and the percentage of single parents in the block group.
11

Percentage of Housing Stock Built After 1980

In this model, newer housing is believed to be a proxy for a number of possible characteristics of

neighborhoods that may influence the likelihood of a “walking along roadway” crash. It is 

Table 5. Effects of marginal changes in independent variables in the binary logistic model.

Variable 

Mode

or

Mean 

Coefficient

(Estimate)

p-Value

(Significance)

Probability

Site Is a

Crash Site at

Mean/Mode

Probability Site 

Is a Crash Site

With Marginal

Change

Constant -8.8161 0.0002

Paved Sidewalk Absent 1 1.9903 0.0572 0.4771 0.1109

Speed Limit (mi/h)* 

Divided by 5 8 0.8135 0.0572 0.4771 0.6730

Paved Shoulder Greater

Than 0.76 m (2.5 ft) 0 31.1738 0.0210 0.4771 1.0000

Paved Shoulder Dummy

Variable Interacted With

Speed Limits 0 -3.3395 0.0171 1.0000 0.9875

Grassy and Other

Unpaved Shoulder Space 1 -2.3327 0.0062 0.4771 0.9039

Percentage of Single

Parents With Children 7 0.2646 0.0040 0.4771 0.5431

Less than 30 Percent

of Housing Stock Built

After 1980 0 2.4171 0.0129 0.4771 0.9110

More Than 85 Percent

of Households 

Composed of Families 0 -2.1301 0.0416 0.4771 0.0978

Unemployment Less

Than 1.75 Percent 0 -1.9415 0.0322 0.4771 0.1158

Vehicle Volume 280 0.0025 0.0336 0.4771 0.4833

Pedestrian Volume 3 0.0022 0.9821 0.4771 0.4776

* 1 mi/h = 1.6 km/h
12

expected that newer neighborhoods are more likely to contain amenities such as better designed roads,

large yards, and nearby parks. These factors might influence the driving patterns and use of the

roadway by residents. In addition, it is likely that the percentage of newer housing is indicative of higher

property values and more recent development, both indicators of the socioeconomic status of a

neighborhood. For these reasons, it is expected that areas with a small percentage of houses built after

1980 might be more highly correlated with crash sites.

This model supports the hypothesis that older neighborhoods are more likely to have pedestrian/motor

vehicle crashes than newer neighborhoods. The marginal effects indicate that sites in neighborhoods

with less than 30 percent of their housing built since 1980 were 90 percent more likely to be crash sites

than areas with more than 30 percent new homes.

Percentage of Families

The U.S. Census defines a family as “a group of two or more people, one of whom is the householder,

living together, who are related by birth, marriage, or adoption.” Families indicate the presence of

groups of people who can rely on each other for a variety of different resources. The possibility that

another family member will have a vehicle and provide transportation reduces the need for family

members to walk as a form of transportation. Families are also likely to participate in activities together

and provide supervision of other family members and children. Because of these types of behavior, it is

expected that areas with a large proportion of families will be more strongly correlated with the noncrash, faraway comparison sites than with crash sites.

The model supports the hypothesis that having more family households reduces the likelihood of a

location being a crash site. The marginal effects showed that areas with more than 85 percent of

households being families were 79 percent less likely to be crash sites than areas with less than 85

percent families.

Unemployment

Areas with extremely low levels of unemployment are also areas in which individuals could be assumed

to place a high value on their time and personal safety. In addition, employed individuals will probably

have less free time to walk in the street and are also financially more able to own a car and thus take a

greater percentage of their trips by car. For all of these and other possible reasons, it is expected that

areas with very high employment would be less likely to be crash sites than areas with higher levels of

unemployment.

The model supports this hypothesis and had a negative coefficient for the dummy variable testing for

areas with less than 1.75 percent unemployment. The analysis found these locations to be 75 percent

less likely to be crash sites, when compared to neighborhoods with a greater level of unemployment.
13

Pedestrian and Vehicle Volumes

The socioeconomic variables discussed above measure exposure indirectly, whereas pedestrian and

vehicle volumes directly measure exposure. It is expected that greater numbers of either pedestrians or

vehicles would increase the likelihood of a location being a crash site, because greater numbers of

pedestrians and vehicles are present for possible conflict. However, the non-crash, faraway

comparison sites were picked without considering pedestrian or vehicle volumes, so it is expected that

the variations in pedestrian and vehicle volumes should not be substantial.

This model found that pedestrian volume, while higher at the crash sites, was not statistically significant

in this particular sample of sites. This result does not mean that pedestrian exposure is not important. 

Instead, it is clearly the result of pedestrian volumes being relatively low (generally less than 5

pedestrians per hour) at most of the sites and fairly similar between crash sites and control sites. 

Vehicle volume, however, was significant and was positively correlated with crash sites. The marginal

effects showed that the increase from 280 vehicles to 290 vehicles per hour, for example, increased the

likelihood that a location was a crash site by 1.3 percent.

Grassy and Other Unpaved Shoulder Spaces

It was expected that very wide grassy areas and other unpaved shoulder spaces might be less likely to

be crash sites, compared to sites with little or no shoulder. This is because even where sidewalks are

absent, a wide unpaved space on the shoulder provides a safe environment for people to walk. 

Furthermore, it may be less likely for a vehicle to strike a pedestrian on an unpaved shoulder than on a

paved shoulder, because the vehicle must run off the road, causing noise and other disturbances that

could alert the pedestrian and/or the driver to the problem prior to a crash.

A width of 1.2 m (4 ft) is comparable to a narrow sidewalk and is wide enough that it is expected to

provide the average pedestrian with a place to walk off of the pavement. Segments with 1.2 m (4 ft) or

more of walkable unpaved space were expected to be less likely to be a crash site than those without

such space.

The model found that an unpaved shoulder of 1.2 m (4 ft) or more makes a location 89 percent less

likely to be a crash site. This is consistent with the conceptual reasoning on this

variable and suggests that such sites have adequate walking space and are less in need of sidewalks

than sites with less than 1.2 m (4 ft) of walkable unpaved space.

CONCLUSION

Roadway characteristics such as the absence of sidewalks, higher traffic volumes, higher vehicle

speeds, and narrower unpaved shoulders increase the likelihood that a pedestrian/motor vehicle

“walking along roadway” crash will occur. By controlling for these factors, this study also found that

neighborhood factors influence the likelihood of a location being a crash site. Specifically, 

neighborhood characteristics that increase the likelihood of a “walking along roadway” crash include:
14

high percentages of single-parent households, large amounts of older housing (i.e., housing built before

1980), few households composed of families, and high levels of unemployment. It is believed that

neighborhood factors capture the extent and type of exposure (i.e., safe or unsafe walking behavior)

that takes place in conjunction with these factors. 

There are treatments that may decrease the likelihood of a location becoming a crash site. Specifically,

sidewalks appear to be the most appropriate treatment on neighborhood streets, while wide unpaved

shoulders may be more suitable in more rural areas. Furthermore, neighborhoods with larger numbers

of single parents, older housing stock, greater dependency on public transit, fewer families, and higher

unemployment might warrant consideration for improvements to pedestrian facilities. By physically

separating the individual from the traffic, these improvements would provide a safer place for

pedestrians to walk than in the travel lane or on a paved shoulder.

As part of a larger study for the Federal Highway Administration, the results of this study are being

used to develop improved national priorities and guidelines for the installation of sidewalks, walkways,

and shoulders. Providing such facilities for pedestrians will not only reduce pedestrian/motor vehicle

crashes, but also improve pedestrian access. Such facilities also encourage more walking, which

improves the health and longevity of those who walk regularly. Design guidelines for sidewalks are

given in a 1998 report by the Institute of Transportation Engineers entitled, Design and Safety of

Pedestrian Facilities (13).

It should also be mentioned that the analyses in this study were limited to all “walking along roadway”

crashes in Wake County, North Carolina, in a 4-year period (1992-1996). While such a study could

certainly be conducted in other areas of the country, the results here are consistent with the findings of

previous research on roadway and neighborhood issues in terms of factors that affect pedestrian/motor

vehicle crash experience.

Beyond the variables tested here, it is expected that other variables, such as alcohol and drug usage,

crime rate, and other indications of risk-taking, could be successfully incorporated into this type of

model to further explain behaviors that increase the risk of exposure to this type of crash. Even more

appropriate would be more qualitative research involving the interviewing of neighborhood residents

and those familiar with a variety of neighborhoods to determine some of the root causes for the current

levels of risk and what they believe to be locally appropriate countermeasures.

REFERENCES

(1) Hunter, W., J. Stutts, W. Pein, and C. Cox. Pedestrian and Bicycle Crash Types of the

Early 1990s. Publication No. FHWA-RD-95-163. Federal Highway Administration.

(2) Carlin, J.B., P. Taylor, and T. Nolan. “A Case-Control Study of Child Bicycle Injuries:

 Relationship of Risk to Exposure.” Accident Analysis and Prevention, Vol. 27, No. 6, 

1995, pp. 839-844.
15

(3) Knoblauch, R.L., B.H. Justin, S.A. Smith, and M.T. Pretrucho. Investigation of 

Exposure-Based Pedestrian Accident Areas: Crosswalks, Sidewalks, Local Streets, and 

 Major Arterials. Publication No. FHWA/RD-87-038. Federal Highway Administration.

(4) Roberts, I. “Adult Accompaniment and the Risk of Pedestrian Injury on the SchoolHome Journey.” Injury Prevention, Vol. 1, No. 4, 1995, pp. 242-244.

(5) Roberts, I., R. Norton, and B. Taua. “Child Pedestrian Injury Rates—The Importance of

‘Exposure to Risk’ Relating to Socioeconomic and Ethnic Differences in Auckland, New

Zealand.” Journal of Epidemiology and Community Health, 1989.

(6) King, D.M., S.D. Lawson, S. Proctor, and K. Johal. “Child Pedestrian Accidents in Inner

Areas: Patterns and Treatment.” Traffic Management and Road Safety. Proceedings of

Seminar held at the PTRC Summer Annual Meeting, University of Bath, England, from 7-11

September 1987, Vol. P291, 1987, pp. 159-177.

(7) Epperson, B. “Demographic and Economic Characteristics of Bicyclists Involved in

Bicycle-Motor Vehicle Accidents.” In Transportation Research Record 1502.

Transportation Research Board, National Research Council, Washington, D.C., 1995, 

 pp. 58-64.

(8) Christie, N. The High-Risk Child Pedestrian: Socio-Economic and Environmental

Factors in Their Accidents. TRL Project Report, 1995, (PR 117).

(9) Bagley, C. “The Urban Setting of Juvenile Pedestrian Injuries: A Study of Behavioural

Ecology and Social Disadvantage.” Accident Analysis and Prevention, Vol. 24, No. 6, 1992,

pp. 673-678.

(10) Braddock, M., et al. “Using a Geographic Information System to Understand Child

Pedestrian Injury.” America Journal of Public Health, Vol. 84, No. 7, 1994, pp. 1158-

1161.

(11) Stokes, M.E., C.S. Davis, and G.G. Koch. Categorical Data Analysis Using the 

SAS System. SAS Institute, Inc., Cary, NC, 1995.

(12) SAS Institute, Inc. SAS/STAT Software Changes and Enhancements Through Release 

6.11. Cary, NC, 1996.

(13) Institute of Transportation Engineers, Committee TENC-5A-5. Design and Safety of

Pedestrian Facilities. March 1998.
16
 Before After

APPENDIX A. INTERNATIONAL BOULEVARD

SIDEWALK IMPACT STUDY: 

SeaTac, WASHINGTON

by

Richard L. Knoblauch

17
18
19

OVERVIEW

This research was conducted by the Center for Applied Research, Inc., as part of a subcontract from

The University of North Carolina Highway Safety Research Center. Task Order 11, Evaluation of

Pedestrian Facilities, was part of a Federal Highway Administration research project, Pedestrian and

Bicyclist Safety—Administrative and Technical Support.

OBJECTIVES

The purpose of this study was to determine the effect of a major sidewalk installation project along a

12-block section of International Boulevard in SeaTac, Washington (State Highway 99 from S. 188th

Street to S. 200th Street). This stretch of Highway 99 is the area for Phase II of International

Boulevard improvements. The area of observation was defined as the street frontage of International

Boulevard from just north of the intersection with S. 188th Street to just south of the intersection with S.

200th Street.

BACKGROUND

This section of roadway has undergone significant enhancement in the past year. The improvements 

include: new road surface; 2.4-m- (8-ft-)wide sidewalks on either side; street trees; a center median

with trees and an earthen berm; and street lighting on high poles for illuminating the roadway, as well as

smaller lights on shorter poles for illuminating the sidewalks. In addition, a traffic signal with pedestrian

heads and marked crosswalks were installed in the middle of the site at 192nd Street. This intersection

was previously stop-sign controlled on the minor leg. SeaTac has recently incorporated as a city (the

area was previously unincorporated and was administered by King County) and International

Boulevard is the main street through town. Formerly, it was known as State Highway 99, and was the

main artery between Seattle and Tacoma until the construction of Interstate 5 in the early 1960s. As

such, it was developed with an auto-oriented character, and the businesses that lined the street tended

to be motels, gas stations, and fast-food outlets. More recent development and redevelopment have

been influenced by SeaTac International Airport, which is about 0.8 km (0.5 mi) north of the study

area. Currently, the study area includes several motels, fast-food outlets, gas stations, rental car lots,

airport parking lots, office buildings (including the headquarters of Alaska Airlines), small professional

offices (doctors, chiropractors, etc.), a self-storage facility, an apartment building, and several

convenience stores. There has been no significant redevelopment along the study area in the last year. 

Figures 1, 2, and 3 show “before” and “after” views of three different locations along International

Boulevard.

METHOD

The data collection protocol was developed to determine the effect of sidewalk construction on

pedestrian behavior. Because other street improvements (i.e., median, repaving, new crosswalk) were

also done at the same time, it was not possible to attribute any of the effects observed solely to the

sidewalk improvement.
20

Observation Zones: For the purpose of data collection in the field, the study area was divided into 11

zones. The length of these zones ranged from 88 to 169 m (288 to 555 ft). The borders of each zone

were set to conform as closely as possible to pre-construction transitions from one pedestrian surface

to another. The zones included only International Boulevard and the pedestrian areas along the

boulevard and did not extend down any of the intersecting streets or their pedestrian areas.

Observation Periods: Each zone was observed for a period of 10 minutes before the observers

moved to the next zone. The days of the week and the times of the day for observation were chosen so

that the before (1997) and after (1998) periods were comparable. The weather in 1998 was slightly

better than the weather in 1997.

Observation Procedures: During each 10-minute observation period, observers were positioned

near the middle of a zone. They were positioned so that they could see all pedestrians entering and

leaving the zone, as well as those pedestrians moving from point to point within the zone. A data

collection form was developed so that the observers could record the following information:

! Vehicle volumes.

! Vehicle speeds.

! Pedestrians walking:

- Distance walked.

- Location walked (i.e., shoulder, curb, sidewalk).

! Pedestrians crossing:

- In crosswalk.

- Not in crosswalk.

! Pedestrian/vehicle conflicts:

- Signal timing.
21

(a) Before.

(b) After.

Figure 1. Zone 5: Looking south.
22

(a) Before. 

(b) After. 

Figure 2. Zone 5: Looking north.
23

(a) Before. 

(b) After.

Figure 3. Zone 4: Looking north from 192nd Street.
24

RESULTS

The results of the data collection effort are summarized in Table 1. Although northbound volumes 

increased by 9.5 percent, southbound volumes decreased by 10.5 percent. The overall decrease in

volume was 2.2 percent. None of these differences were significant. Vehicle speeds were also

essentially unchanged from 1997 to 1998.

Pedestrian volumes increased by 15 percent from 1997 to 1998, but the difference was not significant. 

The length of the average pedestrian trip increased 33 percent. This difference was significant. 

Apparently, after the improvements, somewhat more pedestrians were walking further. An examination

of the age distribution of the pedestrians observed revealed no meaningful differences. There was a

slight increase in the number of female pedestrians observed (from 30.0 percent to 38.2 percent). It

was also found that pedestrians were more likely (22.7 percent in 1997 vs. 35.2 percent in 1998) to be

traveling in groups. It could be hypothesized that the improvements resulted in a more pedestrianfriendly environment that was more likely to be used by women and groups of pedestrians, but there

was no way to prove this hypothesis. There was no change in the percentage of pedestrians observed

carrying parcels or shopping bags (13.2 percent in 1997 vs. 12.6 percent in 1998).

The changes in pedestrian walking location were more dramatic and very statistically significant. In

1997, almost half (42 percent) of the pedestrians were observed walking on the shoulder and 8

percent were walking along the curb at the shoulder. Installing sidewalks along both sides of

International Boulevard resulted in all of the pedestrians in 1998 walking on the sidewalks. Although

there was a 38-percent increase in pedestrian crossings (from 6.1 pedestrian crossings per hour in

1997 to 8.1 crossings per hour in 1998), this difference was not statistically significant. There was,

however, a statistically significant change in pedestrian crossing location. In 1997, 66 percent of the

crossing pedestrians used one of the marked crosswalks and 7 percent crossed at an intersection, but

not in a crosswalk. In 1998, 89 percent crossed in a marked crosswalk. It was not known whether

this change was attributable to the installation of the signalized intersection at 192nd Street or to the

other changes (i.e., sidewalks and/or median) that were made. There was also a marked decrease in

percentage of mid-block crossings (27 percent in 1997 and 11 percent in 1998). Although it could

have been hypothesized that the reduction in mid-block crossings was due to the addition of continuous

sidewalks on both sides of the roadway, there was no way to prove that this was the case.

In addition to recording specific data on pedestrians in the observation zone being studied, the field

researchers kept a tally of pedestrians seen “jaywalking” (crossing lanes of traffic) outside of the

observation zone. In 1997, there were 6.8 jaywalkers per hour; less than half that number (3.1) of

jaywalkers were observed in 1998. Because jaywalking and conflict data were collected as simple

tallies, statistical analysis is not possible. However, this change supports the reduction in percentage of

crossings that occurred at mid-block locations that was discussed earlier.

For the purpose of this study, “pedestrian/motor vehicle conflicts” were defined as any altered

pedestrian or driver behavior that was apparently intended to avoid a crash. This would include drivers

braking or slowing down or pedestrians slowing or running while crossing in response to an

approaching vehicle. There was a marked reduction in pedestrian/motor vehicle conflicts. In 1997, 2.9

conflicts per hour were observed and the number dropped to 0.9 conflicts per hour in 1998. It is not
25

known whether this reduction was due to the overall reduction in mid-block crossings that was

observed or to the median, which permitted jaywalkers to divide their crossing into two separate,

somewhat safer, crossing events. 

DISCUSSION

Overall, the effects of the International Boulevard improvement project appeared to be very positive. 

More pedestrians were walking further and they were no longer walking along the shoulder. There

were also reductions in mid-block crossings, jaywalking, and pedestrian/motor vehicle conflicts. 

Although it was not possible to determine that the changes were directly attributable to any one of the

improvements (e.g., sidewalks, median, or additional signalized intersection), there is little doubt that the

entire improvement project resulted in a safer, more pedestrian-friendly environment.

Table 1. Results of the International Boulevard sidewalk improvement project.

Data Element Before

(1997)

After

(1998)

Significance

Test

Significance

Level

Vehicle Volume:

Northbound

Southbound

792 veh/h

1,112 veh/h

867 veh/h

995 veh/h

t = 7.881

t = 0.799

0.444 NS*

0.950 NS

Vehicle Speeds 75.0 km/h

(46.6 mi/h)

74.4 km/h

(46.2 mi/h)

t = 0.087 0.931 NS

Pedestrian Volume 24.0 ped/h 27.7 ped/h t = 0.726 0.469 NS

Distance Walked, Average

Pedestrian Trip Length

 63 m

(205 ft)

84 m

(275 ft)

t = 2.216 0.029

Pedestrians Walking: 

On Sidewalk

Curb, at Shoulder

On Shoulder

42%

 8%

50%

100% Pearson Chi

Square =

304.312

0.000

Crossings, per Hour per Zone 6.2 8.1 t = 0.644 0.521 NS

Pedestrian’s Crossing Location:

In Marked Crosswalk

In Unmarked Crosswalk

Mid-Block

66%

 7%

27%

89%

 0%

11%

Pearson Chi

Square =

18.328

0.000

Pedestrians Jaywalking, per

Hour

6.8 3.1 N/A**

Pedestrian/Motor Vehicle

Conflicts, per Hour

2.9 0.9 N/A

*NS- Not significant.

**N/A- Not applicable.
26
27

APPENDIX B. RECOMMENDED PRIORITIES 

AND GUIDELINES FOR SIDEWALKS AND

WALKWAYS

by

Charles V. Zegeer, Peter Lagerwey, 

Mike Cynecki, Michael Ronkin, 

Cara Seiderman, and Arthur Ross
28
29

INTRODUCTION

According to A Policy on Geometric Design of Highways and Streets, (also known as the American

Association of State Highway and Transportation Officials’ “Green Book”): "Providing safe places for

people to walk is an essential responsibility of all government entities involved in constructing or

regulating the construction of public rights-of-way."

It is a basic principle that there should be well-designed safe places for people to walk along all public

rights-of-way. How this will be accomplished will depend on the type of road, whether it is new

construction or a retrofitted area, and available funding.

On February 24, 1999, Federal Highway Administration (FHWA) Administrator Kenneth R. Wykle, in

a memorandum to FHWA field offices, stated, "We expect every transportation agency to make

accommodations for bicycling and walking a routine part of their planning, design, construction,

operations, and maintenance activities." Again, on February 28, 2000, Administrator Wykle sent a

memorandum to the field offices in transmitting the new Design Guidance language called for in the

Transportation Equity Act for the 21st Century (TEA-21). The guidance, entitled "Accommodating

Bicycle and Pedestrian Travel: A Recommended Approach – A U.S. DOT Policy Statement on

Integrating Bicycling and Walking Into Transportation Infrastructure," states that bicycling and walking

facilities will be incorporated into all transportation projects unless "exceptional circumstances" exist. The

exceptional circumstances are spelled out, and he asked the division offices to work with State

departments of transportation (DOTs) in the implementation of the guidance.

Government agencies at the State, regional, and local levels are developing regulations for funding,

installing, and retrofitting sidewalks. Because there is a great need to improve sidewalk facilities, it is

important for these transportation agencies to direct funding to sidewalk improvement and installation

projects that will be most beneficial to the safety and mobility of all citizens. 

This document is intended to provide agencies at the State, regional, and local levels with tools that they

can use to develop guidelines for creating places for people to walk.

This document is limited to creating guidelines for sidewalks that address only one major pedestrian

need; other needs that merit further consideration include the ability to cross a street and intersection

design.

BASIC PRINCIPLES

Many communities may wish to revisit their roadway planning and rehabilitation criteria. Policies,

standard plans, subdivision regulations, and right-of-way requirements should be considered to make

sure that sidewalks are included in new construction and rehabilitation projects.
30

Goals and Objectives

Typically, communities should focus on: (1) improving conditions for people who are currently walking

(including improved accessibility to sidewalk facilities for pedestrians with disabilities), 

(2) increasing levels of walking, and (3) reducing the number of crashes involving pedestrians. Setting

targets will help in the development of criteria for installing and retrofitting sidewalks.

Pedestrian Facilities

There are several ways in which pedestrians can be accommodated in the public right-of-way:

Sidewalks: Sidewalks on both sides of a street are generally the preferred pedestrian facility. They

provide the greatest degree of comfort for pedestrians and the presence of sidewalks has been

associated with increased safety for pedestrians. The Uniform Vehicle Code defines a “sidewalk” as that

portion of a street between the curb lines, or the lateral lines of a roadway, and the adjacent property

lines intended for use by pedestrians. In most cases, sidewalks are paved, usually with concrete. To

comply with Federal Americans With Disabilities Act (ADA) guidelines, newly constructed sidewalks

must be accessible to people with disabilities.

Off-Road Paths: An off-road path—paved or unpaved—can be an appropriate facility in rural or

low-density suburban areas. A path is generally set back from the road and separated by a green area

or trees. Paths can be flexible in that they can deviate from the exact route of a road in order to provide

more direct access for key destinations. Paths that generally follow the roadway alignment are

sometimes known as "side paths." 

Shoulders: Wide shoulders on both sides of a road are the minimum requirement for providing at least a

possible place for people to walk. They are not as safe as paths or sidewalks, but they are better than

nothing. Shoulders are also beneficial for motorists and cyclists, and future sidewalks or paths should be

created in addition to, not in replacement of, the shoulders.

Shared Streets: In very limited unusual circumstances, it may be possible to allow shared use of a

street for people walking and driving. These are usually specially designed spaces such as pedestrian

streets or "woonerfs.” Guidelines for developing these kinds of places can be found elsewhere in the

FHWA’s Pedestrian Facilities Users Guide: Providing Safety and Mobility (see

www.walkinginfo.org).

New Construction and Retrofitting

Places for people to walk should be provided in all new construction. Retrofitting will require priorities

to be set, and these guidelines are intended to help identify where the need is greatest for adding

sidewalks and other facilities.
31

NEW CONSTRUCTION

New Sidewalk Installation 

All new construction must include places for people to walk on both sides of a street or roadway. New

construction in urban and suburban areas should provide sidewalks. Recommended guidelines for new

sidewalk and walkway installation are given in Table 1. 

Phased Development of Sidewalks

In developing and rural areas, it may be acceptable – although less desirable – to start with shoulders

and unpaved paths and then phase in sidewalks as development accelerates. Criteria for installing

sidewalks along with new development should be implemented with the following in mind:

Space for Future Sidewalks: Space for future sidewalks must always be secured and/or reserved

when a new right-of-way is being created or an existing one is being developed. If roadways are to be

widened, additional right-of-way must be acquired; existing sidewalks should not be narrowed to

accommodate a wider roadway. 

“Triggers” for Future Sidewalk: In rural settings, if sidewalks are not installed at the time of

development, guidelines are needed to determine when sidewalks will be required and how they will be

funded. For example, sidewalks might be required on residential streets once an area has a density of

more than four dwelling units per acre and on arterial streets once they are within a school walking zone

or have transit service.

Funding for Future Sidewalks: If sidewalks are not installed at the time of development, there needs

to be clear regulations as to who (developer, property owner, or governmental agency) will pay for the

sidewalks. Whoever is paying for the road must pay for the sidewalk. If there is money for a road, there

is money for a sidewalk. Developer contributions to sidewalks must be set aside in an account at the

time of development.

Retaining Rural Character

There is a desire in some residential developments to retain a rural atmosphere. Very often this occurs in

places that are not truly rural, but rather suburban or exurban (they may have been rural before being

developed). Frequently, it is in such places that pedestrian crashes occur that are directly attributable to

pedestrians not having places to walk. To address both the goal of having safe places to walk and the

desire of the community to retain a certain atmosphere, path systems can be developed that do not look

like traditional sidewalks, but do meet walking needs. Even in rural areas, people do want to walk and

such facilities should be provided.

Developers in outlying areas may argue that the land use will never fully develop into a pedestrian area.

Given that people walk despite not having facilities – for exercise, going to friends’ houses, accessing 
32

Table 1. Recommended guidelines for new sidewalk/walkway installation. 

Roadway Classification

and Land Use

Sidewalk/Walkway

Requirements Future Phasing

Rural Highways (<400 Average

Daily Traffic [ADT])

Shoulders preferred, with a minimum

width of 0.9 m (3 ft)

Secure/preserve right-of-way

(ROW) for future sidewalks.

Rural Highways

(400 to 2000 ADT)

1.5-m (5-ft) shoulders preferred, 

and minimum of 1.2-m (4-ft)

shoulders required.

Secure/preserve (ROW) for

future sidewalks.

Rural/Suburban Highway

(ADT >2,000 and

Less Than 1 Dwelling Unit

(d.u.)/.4 hectares (ha) 

[1 d.u./acre]) 

Sidewalks or side paths preferred.

Minimum of 1.8-m (6-ft) shoulders

required.

Secure/preserve (ROW) for

future sidewalks.

Suburban Highway

(1 to 4 d.u/.4 ha [1 to 4 d.u.

/acre])

Sidewalks on both sides required.

Major Arterial (residential) Sidewalks on both sides required.

Urban Collector and Minor

Arterial (residential)

Sidewalks on both sides required.

Urban Local Street

(Residential—Less than

1 d.u /.4 ha [1 d.u./acre])

Sidewalks on both sides preferred. 

Minimum of 1.5-m (5-ft) shoulders

required.

Secure/preserve (ROW) for

future sidewalks.

Urban Local Street

(Residential—1 to 4 d.u./.4 ha

[1 to 4 d.u./acre])

Sidewalks on both sides preferred. Both sides required if density

becomes greater than 4 d.u./ .4

ha (4 d.u./acre) or if schools,

bus stops, etc. are nearby.

Local Street

(Residential—More than 

4 d.u./.4 ha [4 d.u./acre])

Sidewalks on both sides required.

All Commercial Urban Streets

(Commercial Areas)

Sidewalks on both sides required.

All Streets in 

Industrial Areas

Sidewalks on both sides preferred. 

Minimum of 1.5-m (5-ft) shoulders

required.

1 acre = 0.4 hectares (ha) 
33

transit, etc. – it is neither rational nor acceptable to build places that do not have places for people to

walk. Residential developments that were added in suburban areas, until recently, typically had

sidewalks. And they functioned very well.

Sidewalks may not be needed on short residential cul-de-sacs (61 m [200 ft] or less), if there is a system

of trails behind the houses and driveway aprons are properly constructed for pedestrians with

disabilities. However, it is not a good practice to have an entire neighborhood without sidewalks.

Sidewalk Continuity

Sidewalks should be continuous; interruptions may require pedestrians to cross a busy arterial street

mid-block or at an unsignalized location in order to continue walking. Sidewalks should also be fully

accessible to side streets and adjacent sidewalks and buildings.

RETROFITTING SIDEWALKS

Many of the streets built in recent decades do not have sidewalks, and these streets need to be

retrofitted. In other cases, existing sidewalks need to be replaced. Establishing priorities for installing

sidewalks involves three steps: (1) develop a prioritized list of criteria, (2) develop a methodology for

using the criteria to evaluate potential sites, and (3) create a prioritized list of sites for sidewalk

improvements.

Criteria

The following are suggested criteria for establishing priorities. Select three or more of them when

developing your own set of criteria. The key is to select criteria that produce the outcomes desired for

your community.

Speed: There is a direct relationship between speed and the number and severity of crashes; high-speed

facilities may rank higher if speed is a criterion.

Street Classification: Arterial streets should take precedence, because they generally have higher

pedestrian use (due to more commercial uses) and a greater need to separate pedestrians from motor

vehicles (due to higher traffic volumes and speeds). Also, arterials are the main links in a community.

Crash Data: Pedestrian crashes seldom occur with high frequency at one location, but there are clearly

locations where crashes occur due to a lack of sidewalks. Usually, there is a pattern of pedestrian

crashes up and down a corridor, indicating a need to provide sidewalks throughout, not just at crash

locations.

School Walking Zones: School walking zones typically extend from residential areas to an elementary

school. Children are especially vulnerable, making streets (especially arterials) in these zones prime

candidates for sidewalk retrofitting. 
34

Transit Routes: Transit riders need sidewalks to access transit stops. Arterials used by transit are

prime candidates for sidewalk retrofitting.

Neighborhoods With Low Vehicle Ownership: Twenty percent of the U.S. population has a

disability and 30 percent of the population does not drive. Walking is the primary mode of transportation

for many of the people in this country. People with disabilities live throughout the community. If they are

not seen in the community, it may be due to the fact that adequate facilities are not provided. In addition,

car ownership is lower and crash rates are often higher in low- and moderate-income neighborhoods

with lots of children. Therefore, some locations with high pedestrian use (neighborhoods with more

children and elderly persons and where vehicle ownership is low) should be given special consideration

for sidewalks.

Urban Centers/Neighborhood Commercial Areas: Areas of high commercial activity generate high

pedestrian use, even if they are primarily motorists who have parked their cars. Sidewalks are needed to

improve safety and enhance the economic viability of these areas.

Other Pedestrian Generators: Hospitals, community centers, libraries, sports arenas, and other public

places are natural pedestrian generators where sidewalks should be given priority.

Missing Links: Installing sidewalks to connect pedestrian areas to each other creates continuous

walking systems. 

Neighborhood Priorities: Local residents may have a sense of where the most desired walking routes

exist. Neighborhood groups or homeowners associations can provide a prioritized list of locations

where they see a need for sidewalks. Agencies should be cautious about using this criterion, as it is not

desirable to let neighborhood pressure override addressing a key safety concern. However, it may be

useful to monitor requests from pedestrians with disabilities.

Methodology

The two recommended methodologies for selecting locations for improvement are: (1) the overlapping

priorities method, and (2) the points method. Establishing priorities should consume only a small

percentage of a program budget—the level of effort put into prioritization should be proportionate to the

size of the capital budget. 

There is no single right way to select which criteria to use when developing priorities. The criteria and

methodology should balance safety measures, such as vehicle speed and pedestrian crash data;

pedestrian usage measures, such as proximity to schools or commercial areas; continuity between origin

and destination; and accessibility for pedestrians with disabilities.

Overlapping Priorities Method: The easiest and cheapest way to identify overlapping priorities is

through graphical representation. The intent is to identify locations that meet multiple criteria. This

methodology is especially useful in cases where there is not a lot of staff time and funding for detailed

analysis. It can be accomplished using a GIS system or it can be done by hand. 
35

The best way to describe this methodology is by example. Assume that priorities are going to be

developed based on transit routes, proximity to schools, people with disabilities, and neighborhood

commercial areas. Start with a map of your jurisdiction. Using a colored pen, identify those arterials that

have high transit use. Draw a half-mile circle around every elementary school and around locations that

attract people with disabilities. Color in the neighborhood commercial areas. This visual approach will

make areas of overlapping priorities become immediately clear. The streets without sidewalks within the

overlapping areas are the highest priority for retrofitting sidewalks.

Points Method: A weighted points system can be used where staff time and funding are available for

more detailed analysis, or if there is a large amount of capital available for side- walk construction. If

there are a lot of competing projects, a more sophisticated point system can be used to explain to the

public why certain projects were funded and others were not. 

A point system can be developed in many ways. The system should be simple and produce desired

outcomes. Any and all of the criteria listed above can be assigned a range of numbers and then be used

to analyze the need for improvement at given locations. For example, a corridor could be assigned

points based on the number of “walking along roadway” crashes over a 5-year period; the number of

buses that travel the corridor during peak times; and the proximity to elementary schools. This method is

time-consuming because it will be necessary to analyze multiple locations with sidewalk needs to create

a list of priority projects.

Prioritized List: Both the overlapping priorities and the points methods will produce an initial list of

prioritized projects. The next step is to refine the list so that it works, using common sense. One

important consideration is that when roadways are resurfaced, rehabilitated, or replaced, curb ramps

must be added if there are pedestrian walkways. In addition, the U.S. Department of Justice considers

bus stops to be pedestrian walkways requiring access for people with disabilities, so areas near transit

should be given priority accordingly. Improving pedestrian crossings, particularly on arterial streets, may

also be an important part of some projects. Other important questions include: Are priority locations

ones that might be expected? Are there many surprises? Are priority locations in line with community

priorities and expectations? Are some priorities at locations with very low pedestrian use? If the answer

to these questions is "yes," then the criteria or the methodology should be evaluated and possibly revised

to create outcomes that better reflect expectations and desires. The methodologies should be used to

prioritize known needs, not to create a new set of priorities that don’t make sense. 

The final step is to create packages of fundable projects. The prioritization process should result in

reasonable packages that decision-makers can embrace and support. For example, it may be possible

to install sidewalks on both sides of every arterial within a half mile of every elementary school for 5

million dollars over a period of 5 years. Or, it may be possible to replace sidewalks in neighborhood

commercial areas for 2 million dollars over a period of 3 years. The objective is to take what may

appear to be an unsolvable problem (endless need for more funds) and to package it in such a way that

it begins to address some of the most critical pedestrian needs in a community.
36

SIDEWALK DESIGN GUIDELINES

Sidewalk Placement in Large and Small Cities 

Continuous sidewalks should be placed along both sides of all fully improved arterial, collector, and local

streets in urban and suburban areas. Sidewalks should connect to side streets and adjacent buildings.

Accessible crossings should be provided across median islands, frontage road medians, and other raised

islands.

Case Study: Seattle

Seattle recently completed an inventory of all sidewalks in the city using a three-step process: 

! An intern was hired to review aerial photographs to determine whether a sidewalk existed. This

information was then recorded as a new layer on the existing GIS street database. 

! The intern field-checked all locations where there was some uncertainty regarding the presence of a

sidewalk (about 10 percent of the aerial photographs were not clear). 

! Each of 13 neighborhood groups that cover the city were given a draft copy of the inventory and

were asked to check it for errors. 

The total effort took the equivalent of one full-time person working for 6 months in a city with a

population of 530,000, 218 km2 (84.3 mi2) of land use, and 2,659 roadway km (1,652 roadway mi)

comprised of 1,934 residential street km (1,202 residential street mi) and 724 arterial km (450 arterial

mi). Once the inventory was completed, the information was combined on a map with three other types

of information: 

School Walking Zones: A colored circle identified a half-mile area around each school.

Pedestrian Generators: A second color was used to identify a half-mile area around key pedestrian

generators, such as hospitals, libraries, and community centers. 

Neighborhood Commercial Areas: A third color was used to identify the dozen neighborhood

commercial areas in Seattle (approximately one for each of the major neighborhood areas). 

Once the map was printed, it was very easy to see where three colors overlapped, two colors

overlapped, etc. The final step was to have the computer calculate the sidewalk deficiencies in the

overlapping areas. They found, for example, that there were less than 3.2 km (2 mi) of arterial streets

that were within school walking zones, a pedestrian generator area, and a neighborhood commercial

area that did not have sidewalks on either side of the street. 

There were nearly 4.8 km (3 mi) of arterial streets that were within school walking areas, but were

outside of neighborhood commercial areas and pedestrian generators, that did not have 
37

sidewalks on either side of the street. There was a citywide deficiency of more than 32 km (20 mi) of

arterial streets that lacked sidewalks on both sides of the street.

By developing these and other measurements, the pedestrian program was able to put together

packages of information that demonstrated what could be accomplished with additional funding. What

everyone thought was an unsolvable multi-million-dollar problem was reduced to a series of smaller,

fundable projects that decision-makers could endorse. The result was increased 

funding and a new optimism that meaningful progress could be made on solving Seattle’s sidewalk

deficiencies.

Sidewalks, Walkways, and Shoulders in Rural Areas 

A safe walking area must be provided outside the motor vehicle roadway. Sidewalks along rural roads

should be well separated from the roadway. Isolated residential areas should have a pedestrian

connection to the rest of the rural community for school access, shopping, and recreational trips.

An off-road path—also known as a side path—is a type of walkway used in some rural settings. This

path, which may be paved or unpaved, is separated from the roadway by a grass or landscaped strip,

without curbing. This maintains a rural look, but is safer and more comfortable than a shoulder.

A paved or unpaved shoulder should be provided as a minimum along the road. Paved shoulders are

preferred to provide an all-weather walking surface and they also serve bicyclists and improve the

overall safety of the road. A 1.5-m- (5-ft-) wide shoulder is acceptable for pedestrians along lowvolume rural highways. Greater width, up to 2.4 to 3.0 m (8 to 10 ft), is desirable along high-speed

highways, particularly those with a large number of trucks. An edgeline should be marked to separate

the shoulder from the roadway.

Sidewalk Width

The width of a sidewalk depends primarily on the number of pedestrians who are expected to use the

sidewalk at a given time – high-use sidewalks should be wider than low-use sidewalks. "Street furniture"

and sidewalk cafes require extra width, too. A sidewalk width of 1.5 m (5 ft) is needed for two adult

pedestrians to comfortably walk side by side, and all sidewalks should be constructed to be at least this

width. The minimum sidewalk widths for large or small cities are: 

Local or collector streets 1.5 m (5 ft)

Arterial or major streets 1.8 to 2.4 m (6 to 8 ft)

Central business districts 2.4 to 3.7 m (8 to 12 ft)*

Along parks, schools, and other

 major pedestrian generators 2.4 to 3.0 m (8 to 10 ft)

*A 2.4-m (8-ft) minimum width is recommended in commercial areas with a planter strip, and a 3.7-m

(12-ft) minimum width is recommended in commercial areas with no planter strip.
38

These widths represent a clear or unobstructed width. Point obstructions may be acceptable as long as

there is at least 914 mm (36 in) for wheelchair maneuvering (no less than 1,219 mm [48 in] wide as a

whole); however, every attempt should be made to locate streetlights, utility poles, signposts, fire

hydrants, mailboxes, parking meters, bus benches, and other street furniture off of the sidewalk. When

that is not possible, sidewalk furnishings and other obstructions should be located consistently so there is

a clear travel zone for pedestrians with vision impairments and a wider sidewalk should be provided to

accommodate these obstructions. 

Similarly, when sidewalks abut storefronts, the sidewalk should be built 0.6 m (2 ft) wider to

accommodate window shoppers, and to avoid conflicts with doors opening and pedestrians entering or

leaving the buildings.

Many 1.2-m (4-ft) sidewalks were built in the past. This width does not provide adequate clearance

room or mobility for pedestrians passing from the opposite direction. All new and retrofitted sidewalks

should be 1.5 m (5 ft) or wider.

Sidewalk Buffer Width

Buffers between pedestrians and motor vehicle traffic are important to provide greater levels of comfort,

security, and safety to pedestrians. Landscaped buffers provide space for poles, signs, and other

obstructions; they serve as a snow storage area; and they protect pedestrians from splash. The ideal

width of a planting strip is 1.8 m (6 ft). Minimum allowable landscape buffer widths are:

Local or collector streets 0.6 to 1.2 m (2 to 4 ft)

Arterial or major streets 1.5 to 1.8 m (5 to 6 ft)

With a landscaped buffer between the sidewalk and the street, care must be taken to ensure that the bus

stops are fully accessible to wheelchair users and have connections to the sidewalk. Irrigation may be

needed in areas with low precipitation.

Buffers also provide the added space to make curb ramps and landings accessible. When the ramps and

landings are designed properly, they are also better utilized by pedestrians pushing strollers or pulling

carts and luggage.

If a planting strip is not provided between the sidewalk and the roadway, then the sidewalk width should

be a minimum of 1.8 m (6 ft). 

Where landscaped sidewalk buffers cannot be provided due to constraints, on-street parking, a

shoulder, or a bicycle lane can serve to buffer pedestrians from motor vehicle traffic lanes. The

overriding principle is that a narrow sidewalk should never be placed right next to moving traffic.
39

Sidewalk Surface

Concrete is the preferred sidewalk surface, providing the longest service life and requiring the least

amount of maintenance. Asphalt is an acceptable walkway surface in rural areas and in park settings,

and crushed granite may also be an acceptable all-weather material in parks or rural areas, but they

generally require higher levels of maintenance and are less desirable for wheelchair users. 

Sidewalks may be constructed with bricks and pavers if they are constructed to avoid settling; bricks

should be easy to reset or replace if they cause a tripping hazard. Also, bricks and/or pavers can cause

vibrations that are painful for pedestrians who use mobility aids and, therefore, it may be appropriate to

use bricks or pavers only for sidewalk borders in certain situations. There are stamping molds that create

the visual appearance of bricks and pavers; these have the advantages of traditional concrete without

some of the maintenance issues and roughness associated with bricks and pavers. There are

commercially available products that produce a variety of aesthetically pleasing surfaces that are almost

impossible to distinguish from real bricks and pavers. However, stamped materials can also have

maintenance issues, since, for example, the sidewalk may never look the same again after repairs are

made.

It is also possible to enhance sidewalks aesthetically, while still providing a smooth walking surface by

combining a concrete main walking area with brick edging where street furniture (lights, trees, poles,

etc.) can be placed. For example, in a central business district, a 4.6-m 

(15-ft) total sidewalk width might include a 2.4-m (8-ft) unobstructed concrete sidewalk with a 2.1-m

(7-ft) edge. 

Sidewalk Grade and Cross-Slopes

Sidewalks should be built to accommodate all pedestrians and should be as flat as practical. Sidewalks

should be held to a running grade of 5 percent or less, if possible. However, for obvious reasons,

sidewalks that follow the grade of a street in hilly terrain cannot meet this requirement and may follow the

grade of the street. The maximum grade for a curb ramp is 1:12 (8.3 percent). 

The maximum sidewalk cross-slope is 1:50 (2.0 percent) to minimize the effort needed for wheelchair

users and still provide drainage. At least 0.9 m (3 ft) of flat sidewalk area is required at the top of a

sloped driveway to accommodate wheelchair use. In some cases, it may be necessary to bend the

sidewalk around the back of the driveway to achieve 0.9 m (3 ft) of level terrain. 

Curb Ramps

Curb ramps must be provided at all intersection crossings (marked or unmarked) and mid-block

crosswalks for wheelchair access. These ramps also accommodate strollers, carts, the elderly, and

pedestrians with mobility limitations. Curb ramps should be as flat as possible and they must have a

slope no greater than 1:12 (8.3 percent). Abrupt changes in elevation at the top or bottom should be

avoided. The minimum curb ramp width is 914 mm (36 in); however, 1,219 mm (48 in) is the desirable
40

minimum. If a curb ramp is located where pedestrians must walk across the ramp, the ramp must have

flared sides of no more than 1:10 (10 percent) slope. These flares are not needed where ramps are

placed in a landscaped area. Curb ramps also require a minimum of 

914 mm (36 in) of level and clear passage (1,219 mm [48 in] or more is desirable) at the top.

Two separate curb ramps, one for each crosswalk, should be provided at each corner of an intersection.

Diagonal curb ramps provide no directional guidance to vision-impaired pedestrians, and force

wheelchair users to maneuver in the crosswalk. Raised islands in a crossing must have at least a 1,219-

mm (48-in) cut-through that is level with the street; this is generally preferable to curb ramps, which

force wheelchair users to go up and down. 

Obstacles Along the Sidewalk

The distance to the bottom of signs placed in or next to a sidewalk should be at least 2.1 m (7 ft) above

the sidewalk surface to avoid injury to pedestrians. Bushes, trees, and other landscaping should be

maintained to prevent encroachment into the sidewalk. Jurisdictions should adopt ordinances requiring

local property owners to trim the landscaping they place along their frontage to maintain unobstructed

sidewalks. The jurisdictions should provide an inspection procedure or a system of responding to

sidewalk encroachment and maintenance complaints.

Guy wires and utility tie-downs should not be located in or across sidewalks at heights below 

2.1 m (7 ft). When placed adjacent to sidewalks or pedestrian walkways, the guy wires should be

covered with a bright yellow (or other high-visibility) plastic “guard” to make the wire more visible to

pedestrians. Guy wires of any color will not be visible to blind pedestrians and must not be located

within the pedestrian route. Other obstacles include signal controller boxes, awnings, temporary signage,

newspaper racks, fire hydrants, and similar items.

Accessibility

The easiest way to visualize accessibility requirements (grade, cross-slope, and unobstructed width) is

with the concept of a "continuous passage." Sidewalks must provide a continuous route at a 2-percent

maximum cross-slope at a minimum width of 0.9 m (3 ft). This does not mean that 0.9 m (3 ft) is an

acceptable sidewalk width, just that at no point shall the level area be less than 0.9 m (3 ft) wide. This

applies mainly at obstructions, driveways, and curb ramps.

Snow

Municipalities that do not remove snow on sidewalks should have an ordinance requiring property

owners to clear the snow and keep the sidewalks accessible to pedestrians. When the latter is the case,

municipalities should educate property owners as to why this is important and have enforcement efforts

in place to ensure compliance.
41

Bus Stops and Shelters

It is generally preferable to place bus shelters between the sidewalk and the street, or between the

sidewalk and adjacent property, so that waiting passengers do not obstruct the flow of pedestrians along

the sidewalk. Benches and other street furniture should be placed outside the walking paths to maintain

the accessibility of the walkway and to provide good pedestrian service. In addition, curb ramps should

be provided at bus stops, because it is not always possible for the bus to pull up close enough to the

curb to deploy a lift.

Lighting

Good streetlighting improves the visibility, comfort, and security of pedestrians. It is impractical to

provide lighting in most rural areas In urban areas, it is important to light at least the intersections and

other pedestrian crossing areas. Lighting is also recommended in areas where there is a high

concentration of nighttime pedestrian activity, such as churches, schools, and community centers. Where

continuous lighting is provided along wide arterial streets, it is desirable to place the lights along both

sides of the street. Continuous streetlights should be spaced to provide a relatively uniform level of light.

In shopping districts or in downtown areas with high concentrations of pedestrians, it may be desirable

to provide pedestrian-level lighting in addition to the streetlighting in order to improve the comfort and

security of pedestrians. The preferred pedestrian-level lights are mercury vapor or incandescent.

Low-pressure sodium lights may be more energy-efficient, but are undesirable because they create

considerable color distortion. Pedestrian-level lighting may also be installed in selected areas of

pedestrian activity to create a sense of intimacy and place.

Other Design Considerations

Sidewalks should be built within the public right-of-way or in a sidewalk easement along the

right-of-way. This will provide access to the sidewalk for maintenance activities and will prevent the

adjacent property owners from obstructing or removing the sidewalk in the future.

Care must be taken to avoid planting trees or large bushes in the landscape buffer area that will obscure

the visibility of a pedestrian attempting to cross or enter a street and an approaching motorist. Trees with

large canopies planted between the sidewalk and street should be generally trimmed up to at least 2.4 m

(8 ft) high and bushes should be kept to about 762 to 914 mm (30 to 36 in) in height. Trees with largecaliper trunks may not be appropriate near intersections and in other situations where they may block

visual sight triangles. 

Meandering sidewalks are sometimes used where a wide right-of-way is available and there is a desire

to provide a high level of landscaping, such as in a park or along a waterway or other natural feature. It

is often believed that meandering sidewalks create a more pleasant walking environment. The reality is

that they unnecessarily create a longer walking distance and are inappropriate for sidewalks along a

street. 
42

Sidewalks should be built along both sides of bridges. Pedestrian rails or guardrails are required along

the outside of the bridge. On bridges with high-speed traffic, concrete barriers between the traveled way

and the sidewalk may be considered to shield pedestrians from errant vehicles. However, this adds cost,

weight, and width to the bridge, and the transition from barrier to guardrail or curb at each end often

creates an awkward transition for pedestrians, who must detour around the barrier to access the bridge

sidewalk.

Rollover curbs should not be used next to sidewalks as they encourage motorists to park on planting

strips or sidewalks. They may be problematic for some visually-impaired people, since they don’t create

a definitive edge between the street and adjacent uses.

Sidewalk Depth: Concrete sidewalks should be built to a minimum depth of 101.6 mm (4 in) and to a

minimum depth of 152 mm (6 in) at driveways.

SIDEWALK COST CONSIDERATIONS

The actual cost of providing sidewalks will be different for each region of the country and varies with the

seasons. Actual bid prices are also influenced by how busy contractors are at the time of construction.

The cost of constructing sidewalks alone is relatively low; typical bids run between $24 and $36/m2 ($20

and $30/yd2), which roughly translates to $43 to $64/running m ($12 to $20/running ft) for 1.82-m- (6-

ft) wide sidewalks. Therefore, sidewalks on both sides of the roadway can run roughly between

$150,000 to $250,000/mi (Oregon DOT, 1999). 

Factors to consider when calculating the cost of sidewalks:

Presence of curb and gutter: The cost of providing curb and gutter, which presumes the need to also

provide a street drainage system, runs much higher than the cost of sidewalk. A standard perpendicular

curb ramp and top landing need a minimum border width of almost 3.7 m (12 ft) at intersections if there

is a 152-mm (6-in) curb. A 152-mm curb reduces the minimum border width to 3.0 (10 ft). Yet, on

many urban streets, this work must be performed prior to installing the sidewalks. If this is the case, only

the cost of the sidewalks and curb ramps should be attributed to expenditures for pedestrians—catch

basins are provided to drain the roadway surface used by motor vehicle traffic.

Number of driveways: To comply with the Americans With Disabilities Act, many existing driveways

must be replaced with ones that provide a level passage at least 0.9 m (3 ft) wide. It can also be

advantageous to inventory all existing driveways to see if any can be closed, resulting in a cost-savings.

Number of intersections: While intersections represent a reduction in the sidewalk, curb ramps are

required where sidewalks cross intersections and the cost of providing additional traffic control at each

intersection should be considered.
43

Obstacles to be removed: The cost of moving or removing obstacles such as power poles, signposts,

and fire hydrants vary too much to be itemized here; however, it is required that they be moved if they

obstruct access. These costs must be calculated individually for each project.

Structures: While minor sidewalk projects rarely involve new structures such as a bridge, many

projects with significant cuts and fills may require retaining walls and or culvert extensions. The cost of

retaining walls must be calculated individually for each project.

Right-of-way: While most sidewalk projects can be built within the existing right-of-way, especially

infill projects, some may require some right-of-way easements. An alternative to acquiring right-of-way

is to narrow the roadway, which should consider the needs of bicyclists (e.g., through bicycle lanes or

shoulders, at a minimum width of 1.5 m [5 ft].

Miscellaneous factors: Planters, irrigation, benches, decorative lampposts, and other aesthetic

improvements cost money, but they are usually well worth it if the impetus for the project is the creation

of a more pleasant and inviting walking environment.

When project costs appear to be escalating due to one or more of the above-listed items, especially

retaining walls or acquiring right-of-way, consideration may be given to narrowing the sidewalk in

constrained areas as a last resort. The full sidewalk width should be resumed in non-constrained areas. 

This is preferable to providing a narrow sidewalk throughout, or dropping the project because of one

difficult section.

Tips to reduce total cost: 

Stand-alone vs. integrated within another project: Sidewalks should always be included in road

construction projects. Stand-alone sidewalk projects cost more than the same work performed as part

of a larger project. Sidewalks can be "piggybacked" onto projects such as surface preservation, water

or sewer lines, or the placement of utilities underground. Besides the monetary savings, the political

fallout is reduced, since the public does not perceive an agency as being inefficient (it is very noticeable if

an agency works on a road and then comes back to do more work later). The reduced impact on traffic

is a bonus.

Combining projects: Cost-savings can be achieved by combining several small sidewalk projects into

one big one. This can occur even if the sidewalks are under different jurisdictions, or even in different

localities, if they are close to each other. The basic principle is that bid prices drop as quantities increase.

BIBLIOGRAPHY

American Association of State Highway and Transportation Officials. A Policy on Geometric Design

of Highways and Streets, 1984.
44

Axelson, P. et. al., Designing Sidewalks and Trails for Access, Federal Highway Administration, July

1999. 

Institute of Transportation Engineers. Design and Safety of Pedestrian Facilities: A Recommended

Practice of the Institute of Transportation Engineers, March 1998.