Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.

Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 38

38
CHAPTER 4
BENEFIT-COST ANALYSIS OF BICYCLE FACILITIES
INTRODUCTION AND PURPOSE Estimates of existing bicycling demand are based on U.S.
census journey to work mode shares. Establish the number of
Based on the research conducted for this project, the team residents within 400-, 800-, and 1,600-m buffers of the facil-
crafted a set of guidelines to be used by transportation pro- ity by multiplying the area of each buffer by a user-supplied
fessionals and government agencies to better integrate the population density. Multiply the number of residents in each
planning of bicycle facilities into the transportation plan- buffer (R) by 0.4, assuming the national averages of 80% of
ning process. The web-based guidelines will assist state residents are adults and 50% of adults are commuters, to cal-
DOTs and other state, regional, and local agencies in con- culate the number of daily commuters. Then multiply this
sidering bicycling in all transportation projects. Additionally, number of commuters in each buffer by the region's bicycle
the guidelines will support local agencies' review of bicycle commute share (C). Use the bicycle commute share for the
projects as part of the transportation improvement plan. Metropolitan Statistical Area (MSA) as the default value; the
Transportation planners will be able to use the guidelines user has the option to enter a commute share for the specific
for the following purposes: area if it is known.
Daily existing bicycle commuters = R · C · 0.4
· Estimating the likely cost of specific facilities based on
type and on key characteristics,
Adult commuters represent only a portion of adult bicy-
· Estimating how a facility will impact the overall bicycling
clists. The team compared U.S. census commute shares to
environment in an area, and implicitly how it will affect
NHTS data and found that the total adult bicycling rate
the amount of riding based on characteristics of the facil-
ranges from the census commute rate at the low end to 0.6%
ity and of the surrounding area,
plus three times the commute rate at the high end (Appen-
· If information is available for calibration, estimating the
dix A). This allows the use of readily available census com-
usage of a facility (and the change in usage of comple-
mute shares to extrapolate total adult bicycling rates (T).
mentary and competing facilities), and
· Estimating the specific types of benefits and their rela- Thigh = 0.6 + 3C
tive sizes based on characteristics of the facility and of
the surrounding area. Tmoderate = 0.4 + 1.2C
Tlow = C
TRANSLATING DEMAND AND BENEFITS
RESEARCH INTO GUIDELINES Multiply the estimated low, moderate, and high rates by the
number of adults--estimated to be 80% of the population--
Demand in each buffer to arrive at the total number of daily adult
cyclists.
Estimating the use of a new facility rests on two main
assumptions. First, all existing commuter bicyclists near a Total daily existing adult cyclists = Tj · R · 0.8
8
new facility will shift from some other facility to the new
one. Second, the new facility will induce new bicyclists as a Additional research (Appendix B) found that people
function of the number of existing bicyclists. Research for who live near a facility are more likely to bike than those
this project uncovered that people are more likely to ride a that do not; multipliers were developed to describe these
bicycle if they live within 1,600 m (1 mi) of a facility than if probabilities. Multiplying the numbers of both commuters
they live outside that distance (Appendix B). The likelihood and total adult cyclists by the likelihood multipliers found
of bicycling increases even more at 800 m and 400 m. The in this research for various buffers around the proposed
team therefore estimates existing and induced demand using facility provides an estimated number of induced cyclists
400-, 800-, and 1600-m buffers around a facility. in each group.

OCR for page 38

39
New commuters = ( Existing commuters ( Ld - 1))
of studies of outdoor recreational activities (Appendix G).
From both NHTS and Twin Cities TBI, the average adult
d = 400, 800, 1, 600 cycling day includes about 40 min of cycling. This is the
amount used, plus some preparation and cleanup time. Mul-
New adult cyclists = ( Existing
g adult cyclists ( Ld - 1)) tiply this by the number of new cyclists minus the number of
d = 400, 800, 1, 600 new commuters. (The value of the facility to new commuters
is counted in the mobility benefit.)
Where
Annual recreation benefit = D · 365
L400m = 2.93
L800m = 2.11
·
( new cyclists - new commuters )
L1600m = 1.39
Reduced Auto Use Benefits
Mobility Benefit
These benefits apply only to commuter and other utili-
This research, based on stated preference analysis, found tarian travel, because it is assumed that recreational rid-
that bicycle commuters are willing to spend, on average 20.38 ing does not replace auto travel. These include reduced
extra minutes per trip to travel on an off-street bicycle trail
congestion, reduced air pollution, and user cost savings.
when the alternative is riding on a street with parked cars (6).
Multiply the total benefit per mile by the number of new
Commuters are willing to spend 18.02 min (M) for an on-
commuters, multiplied by the average round trip length
street bicycle lane without parking and 15.83 min for a lane
from NHTS (L).
with parking. Assuming an hourly value of time (V) of $12,
Then consider two offsetting adjustments that ultimately
the per-trip benefit is $4.08, $3.60, and $3.17, respectively.
leave the total number unchanged. First, there are utilitar-
Multiply the per-trip benefit for the appropriate facility by the
ian riders in addition to commuters and some of these trips
number of daily existing and induced commuters, then dou-
will replace auto trips. Second, not all new bike commuters
ble it to include trips both to and from work. This results in
and utilitarian riders would have made the trip by car; evi-
a daily mobility benefit. Multiplying the daily benefit by
dence from NHTS suggests that something less than half
50 weeks per year and 5 days per week results in the following
of bike commuters use driving as their secondary commuting
annual benefit:
mode. For simplicity, assume that these two factors offset
Annual mobility event = M · V 60 each other, and thus the total amount of new bike commuter
mileage is a reasonable number to use to represent the total
·
( existing commuters + new commuters ) · 50 · 5 · 2 amount of new bike riding substituting for driving.
The benefit per mile of replacing auto travel with bicycle
It should be noted that this methodology assumes that no
travel is a function of location and the time of day. There will
bicycle facility previously existed nearby, aside from streets
be no congestion-reduction benefits in places or at times
with parking. In the this equation, V is divided by 60 because
when there is no congestion. Pollution-reduction benefits will
the M is in minutes and V is in hours; dividing V by 60 con-
be higher in more densely populated areas and lower else-
verts it to minutes so that the result can easily be multiplied
where. User cost savings will be higher during peak periods
by the minutes.
when stop-and-go traffic increases the cost of driving.
Based on reasoning documented in Appendix G, conges-
Health Benefit tion savings will be 0 to 5 cents per mile and pollution sav-
ings from 1 to 5 cents per mile depending on conditions.
An annual per-capita cost savings from physical activity Assume the high end of this range in central city areas, the
of $128 is determined by taking the median value of 10 stud- middle range in suburban areas, and the low end in small
ies (Appendix E). Then multiply $128 by the total number of towns and rural areas. For simplicity, assume that all com-
new bicyclists to arrive at an annual health benefit. muting and utilitarian trips are during congested periods.
User cost savings were determined to be 3 cents per mile dur-
Annual health benefit = total new cyclists · $12
28 ing congested peak periods and 0 otherwise; thus, these are
scaled by location in the same way as congestion savings.
Overall, the savings per mile (S) is 13 cents in urban
Recreation Benefit areas, 8 cents in suburban areas, and 1 cent in small towns
and rural areas.
The "typical" day involves about 1 hr of total bicycling
activity, which is valued at $10 (D), based on a wide variety Reduced auto use benefit = new commuters · L · S · 50 · 5