# Presentation: 149522

## Randomly Selected Examples of Community Impact Assessment Methods I Thought You Might Care to Know

- K. Lynn Berry
- FHWA Resource Center
- Environment Technical Service Team
- Federal Highway Administration Environmental Conference
- June 28-30, 2004  in Alexandria, Virginia

## K. Lynn Berry

- FHWA Resource Center at Atlanta
- Environmental Program Specialist
- Consulting & State DOT experience
- BA Anthropology, Notre Dame and MA Anthropology, U of Denver

- 404-562-3618  klynn.berry@fhwa.dot.gov

**Notes:**
This slide is included so you can have a visual reference when trying to remember who the heck I am . . . And so you have my contact info, in case you have questions about what the heck I said.

“It’s a great picture! It’s just the essence of you,” she wrote.

“Hmm. The essence of me,” I wondered. “I  would've hoped for something a little sexier, more daring . . . less ‘she-likes-to-go-to-conferences-and-take-notes’,” I responded.

“Well, next time go for something off the shoulder,” she reasoned. “The markers and collar bone combination is deadly!”

Background in Cultural Anthropology. We all come at this with different skills, and we must work as a team. You are not expected to know everything about each of the impact areas, or how to conduct every analysis. There is an interdisciplinary team around you. Use them.

## The Randomly Selected Methods

- Bicycle Safety Effects
- Pedestrian Safety Effects
- Barrier Effects
- Access Management Effects

## System User vs. Non-Users

- Generally, improvements to roadways will be BENEFICIAL to users
- PROVIDED, of course, facility investments/upgrades are made uniformly
- But for non-users, we need to consider changes in pedestrian and bicycle safety
- Road crossings, barrier effects
- Bicycle compatibility

## Transportation Choice And Factors Affecting It.

- Four reasons individuals and communities may value having choices among transportation modes:
- To help achieve equity goals.
- To serve as a back-up option for those who can drive.
- To increase transportation system efficiency.
- To increase livability.
- Upgrading roads can increase vehicular traffic
- More likely to be dangerous, difficult to traverse, and unpleasant for bike/ped
- Street widening can create barriers
- Projects can displace or disrupt bike/ped facilities

**Notes:**
To help achieve equity goals. A lack of transportation choice limits the personal and economic opportunities available to people who are physically, economically, or socially disadvantaged. Often, such individuals have less access (or less reliable access) to an automobile, and so may face barriers to mobility in automobile-dependent communities. For example, in such communities, non-drivers may have difficulty attending school or working.

To serve as a back-up option for those who can drive. People who do not habitually use an alternative mode may value its availability at some point in the future or in the case of an emergency. Most people can expect to go through periods when they must rely on alternative modes of transportation, due to age, physical disability, financial constraints, vehicle failures, or major disasters that limit automobile use.

To increase transportation system efficiency. Use of alternative modes can help achieve certain transportation demand management (TDM) objectives, including reduced traffic congestion, facility cost savings, and environmental quality.

To increase livability. Many people enjoy using alternative modes such as walking and bicycling, or riding the bus, and they value living in or visiting a community where these activities are safe, pleasant, and readily available.

## Bicycle Safety Index

- BSI=[AADT/(Lx3100)]+{(S/48)x[(4.25-W)x1.635])}+PF+LF
- Wait! Don’t panic!
- C = (D + V + F) > R
- Change happens when
- 	Desire + Vision + First Steps are greater than Resistance

**Notes:**
Developed by:
Davis, J. 1987. Bicycle Safety Evaluation. Chattanooga, TN: Auburn University, City of Chattanooga, and Chattanooga-Hamilton County Regional Planning Commission

Modified by:
Epperson, Bruce. 1994. “Evaluating Suitability of Roadways for Bicycle Use: Toward a Cycling Level of Service Standard.” Transportation Research Record 1438. Washington, DC: Transportation Research Board, National Research Council, pp. 9-16.

BSI = Bicycle Safety Index for a specific road segment
AADT = Average annual daily traffic
L = Number of traffic lanes
S + speed limit (km/h)
W = width of outside lanes (m)
PF = Sum of pavement factors (look up tables, Epperson 1994 Table 2)
LF = Sum of location factors (look up tables, Epperson 1994 Table 2)

SEE ALSO: Harkey, D.L., D.W. Reinfurt, and A. Sorton. 1998.
The Bicycle Compatibility Index: A Level of Service Concept. Federal Highway Administration, FHWA-RD-98-095. Washington, DC: US Department of Transportation. 

## References

- Developed by:
- Davis, J. 1987. Bicycle Safety Evaluation. Chattanooga, TN: Auburn University, City of Chattanooga, and Chattanooga-Hamilton County Regional Planning Commission
- Modified by:
- Epperson, Bruce. 1994. “Evaluating Suitability of Roadways for Bicycle Use: Toward a Cycling Level of Service Standard.” Transportation Research Record 1438. Washington, DC: Transportation Research Board, National Research Council, pp. 9-16.
- Summarized in :
- Sheeley, J., Forkenbrock, D. and M. Boarnet. DRAFT Nov. 2003. NCHRP Project 8-41 “Effective Methods for Environmental Justice Assessment”

## Pedestrian Street Crossings

- LOS rating
- Intersection performance most important
- Ped./vehicle conflict most likely there
- Pedestrian Delay . . . Too long, and pedestrians will not comply with signals or yield to traffic.
- Reduce delays at intersections, then:
- Will encourage more short trips on foot
- Greater safety for those crossing

**Notes:**
Wellar, Barry. 1998. Walking Security Index; Final Report. Ottawa, Ont.: University of Ottawa Department of Geography.

## Pedestrian Road Crossing LOSValues are average delays in seconds per pedestrian crossing

| LOS | Signalized
Intersection | Unsignalized Intersection | Non-compliance likelihood |
| --- | --- | --- | --- |
| A | <10 | <5  | Low |
| B | 10-20 | 5-10 | Low - Mod |
| C | 20-30 | 10-20 | Mod |
| D | 30-40 | 20-30 | Mod - High |
| E | 40-60 | 35-40 | High |
| F | > 60 | > 45 | Very High |

- Forkenbrock and Weisbrod. 2001.NCHRP Report 456 “Guidebook for Assessing
- the Social and Economic Effects of Transportation Projects”

**Notes:**
The current performance of an intersection and its expected performance after a transportation project in terms of pedestrian crossings are the key ot LOS for foot traffic.

Compare the actual time available for crossings with generally accepted time requirements: crosswalk walking speeds are 1.2 meters per second for most areas and 1.0 m/s for crosswalks serving large numbers of older pedestrians. 

Time available is affected by signal cycles and, in the case of non-signalized intersections, traffic speed and volume.

Identify areas with relatively high demand for walking taking into account factors such as population density; attractions such as schools and commercial districts; and current non-motorized travel.  Conduct surveys & interviews.

Adapted from Milazzo, Joseph S II, Nagui M. Rouphail, Joseph E. Hummer and D. Patrick Allen. 1999. “Quality of Service for Interrupted-Flow Pedestrian Facilities in the Highway Capacity Manual 2000,” Transportation Research Record 1678. Washington, DC: Transportation Research Bord, National Research Council, pp. 25-31.

## Barrier Effect Analysis

- Calculate Barrier Size
- AADT, correction factor for trucks, flow speed
- Calculate Crossing Potential (the demand for road crossings)
- Look up table, based on experimental data, taking into account number of residential, commercial, recreational and municipal destinations

**Notes:**
Rintoul, Donald. 1995. Social Cost of Transverse Barrier Effects. Planning Services Branch. Victoria, B.C.: British Columbia Ministry of Transportation and Highways.

Step 1: The barrier size is calculated based on traffic volumes, average speed, share of trucks,number of pedestrian crossings, and length of roadway under study.
B = q × kl × kh  where:
B = barrier size   q = average annual daily traffic  kl = correction factor for trucks, 0.667 + 3.33 x percentage of trucks    kh = (v/50)4 where v = average traffic flow speed (km/h)

Step 2: The demand (i.e., crossing potential) for road and street crossing is calculated based on
residential, commercial, recreational, and municipal destinations within walking and
bicycling distance of the road. The resulting estimate represents the maximum possible
number of non-motorized trips, assuming that there is no traffic barrier to walking and
cycling. For a small study area, this can be done using maps to mark major origins (e.g.,
housing) and pedestrian destinations (e.g., schools, parks, transit stops, and commercial
areas).
CP = d × ∑ (p × cpf ) 
where:
CP = crossing potential
d = population density (persons per km2)
p = portion of total population for each age range
cpf = crossing potential factor for each age range, indicated in Table 5.9 below

Table 5.9. Crossing potential factor (cpf)
Age range cpf
Infant/Toddler (0-4 yrs) 0.42
Elementary (5-12 yrs) 5.0
Secondary (13-17 yrs) 7.0
Adult (18-65 yrs) 2.6
Senior (more than 65 yrs) 0.74
SOURCE: Rintoul 1995, p. 9. Values are based
on experimental data.

## Barrier Effect Analysis, cont.

- Calculate Disruption (amount of exposure of peds and cyclists to traffic)
- Barrier Size and Crossing Potential combined, with adjustments for controlled crossings and weighting by age
- Rintoul, Donald. 1995. *Social Cost of Transverse Barrier Effects*. Planning Services Branch. Victoria, B.C.: British Columbia Ministry of Transportation and Highways.
- ( Summarized in NCHRP Report 456 “Guidebook for Assessing the Social and Economic Effects of Transportation Projects”)

**Notes:**
Step 3: The barrier size and the potential daily crossings are combined to yield a measure of total disruption per kilometer of barrier. The total disruption represents the amount of exposure of pedestrians and cyclists to vehicular traffic.
TD = A× CP × R× B
where:
TD = total disruption per kilometer of barrier
A = adjustment for controlled crossing (A= 1–% utilization of the crossing)
CP = crossing potential, as previously discussed
R = relative disruption factor, an approximate weighting by age (infant = 24,
elementary age child = 16, secondary education child = 4, adult = 1,
and senior citizen = 4)
B = barrier size, as previously discussed

The relative disruption factor takes into account the fact that street crossing causes
different levels of disruption for various age groups. This difference is due to such factors as ability to correctly assess risk, mobility, and ability to use other transportation modes. Although somewhat arbitrary, it provides a greater degree of realism.

Measurement and presentation. The results of barrier effect analysis are presented in terms of total units of disruption. The best use of this numerical result is to compare it with a parallel analysis of an upgraded roadway (or pedestrian facility) to see in fractional terms how much the amount of disruption per kilometer would change.

## Pass-by traffic effectCol. E = [Col. B x (1 + Col. C) x (1 – Col. D)] – [Col. B]

**Notes:**
Spreadsheet model of pass-by traffic effects. A new highway median and
intersection increase traffic throughput and total volumes passing by stores, but the upgrade also eliminates direct driveway access to some businesses. In this example, a four-step process is appropriate:
1) Compile an inventory of businesses along the affected route. This corresponds to column A in Table 8.1.
2) Use business or customer interview data to estimate the extent to which each business along the route depends on pass-by traffic. Alternatively, professional judgement based on direct observations or results from prior studies may be used to estimate the degree of business sensitivity to pass-by traffic. This corresponds to column B in Table 8.1. (In this example, it is assumed that a business’ customers either are going especially to that business destination or are pass-by travelers who stop at the business when they see its sign and a driveway that is easily accessible from the road.)
3) Obtain estimates of the expected change in traffic levels along various portions of the corridor, as well as estimates of the extent to which various business locations would lose some direct access to traffic unable to turn from the other side of the road. This corresponds to columns C and D in the table below.
4) Use a spreadsheet representation of a table like Table 8.1 to calculate the resulting effect on business sales. The basic formula for estimating the overall change in retail sales is:
Col. E = [Col. B x (1 + Col. C) x (1 – Col. D)] – [Col. B]
This general approach is further explained and a spreadsheet model provided in Weisbrod and Neuwirth (1998). NEXT SLIDE

## Reference

- Weisbrod, Glen and R. Neuwirth. 1998. “Economic Effects of Restricting Left Turns.” NCHRP Research Results Digest No. 231. Washington, DC: Transportation Research Board, National Research Council.

## http://www4.trb.org/trb/crp.nsf/All+Projects/NCHRP+25-04 

- _[http://www4.trb.org/trb/crp.nsf/All+Projects/NCHRP+25-04](http://www4.trb.org/trb/crp.nsf/All+Projects/NCHRP+25-04)__ _

**Notes:**
The principal investigator (Glen Weisbrod) developed a Microsoft Excel spreadsheet based on the analysis framework which can be downloaded here. 

## ECONOMIC IMPACTS OF ACCESS MANAGEMENT

- Studies generally indicate that median projects have little overall adverse impact on business activity
- Destination type businesses, such as certain restaurants and specialty stores, appear less sensitive to access changes
- Businesses that rely primarily on pass-by traffic, such as gas stations or convenience stores: more sensitive

- .

*Kristine M. Williams, AICP, Center for Urban Transportation Research, University of South Florida, Tampa, January 28, 2000*

**Notes:**
Prepared by Kristine M. Williams, AICP, Center for Urban Transportation Research, University of South Florida, Tampa, January 28, 2000.

Several studies were conducted in the 1990s to help fill the need for more
information on the potential economic effects of access management. These studies have focused largely on the potential impacts of left-turn restrictions (median projects) on business activity, although some have also addressed changes to driveway access. 
Michael Rees, Tim Orrick, and Robert Marx, “Police Power Regulation of Highway Access and Traffic Flow in the State of Kansas,” presentation, 79th Annual Meeting of the Transportation Research Board, Washington D.C., January 10, 2000.
Eisele, W.L., W.F. Frawley, “A Methodology for Determining Economic Impacts of Raised Medians: Data Analysis on Additional Case Studies.” Research Report 3904-3, Texas Transportation Institute, College Station, Texas. October 1999.
Iowa State University, Iowa Access Management Research and Awareness Project: Executive Summary, 1997.
Ivey, Harris and Walls, “Districtwide Median Evaluation Technical Memorandum: Corridor Land Use, Development & Driver/Business Survey Analysis,” prepared for FDOT District 5, 1995.

## Study Methods

- “Before” and “After” aerial photography
- Historical land uses and property values for parcels (appraisals, CDs)
- Surveys/prearranged on-site interviews
- did not ask for sales details
- General perceptions: better/worse/same
- Field investigations
- Public Involvement: address perceptions and anxiety

**Notes:**
Due to the proprietary nature of sales information and the variety of factors that affect business activity, analysis of this issue has been difficult. Most studies have focused on business owner perceptions of impacts, before and after case examples, or generalized comparisons of business activity across corridors.

TX DOT: Researchers found that prearranged on-site interviews worked far better than telephone or mail surveys, which had very low response rates. Another suggested method was to obtain the endorsement of area Chambers of Commerce prior to approaching business owners for information. A letter of endorsement, signed by the appropriate Chamber of Commerce representative was sent to each of the business owners asking for their cooperation in the study. 
Due to the sensitivity of information on business activity, researchers did not ask for sales details, but for general perceptions as to whether business activity had changed over time using ranges (e.g. better/worse/same). Information on historical property values was obtained through the use of appraisal district computers or by purchasing CDs from private companies with this information.

Although medians do not appear to have a significant adverse economic impact on corridor businesses, such projects do tend to invoke anxiety among affected business owners. One solution is direct and meaningful involvement of affected businesses in median issues.
K. Williams, “Public Involvement in Median Projects,” Proceedings of the Urban Street Symposium, Transportation Research Board, Dallas, TX, 1999. See als o: Public Involvement Handbook for Median Projects, Center for Urban Transportation Research, University of South Florida, Tampa, 1994 (available at www.cutr.eng.usf.edu.)

## Texas DOT

- Perception worse than reality
- Business owners reported no change in pass-by traffic after median installations
- Restaurants and specialty retail reported increases in sales
- Gas stations and repair shops reported decreases
- Most impacts during construction

**Notes:**
Texas 1999
A study of the economic impacts of left-turn restrictions. 

Perceptions of business owners before a median was installed were more pessimistic than what usually happened.
Business owners reported no change in pass-by traffic after median installations.
Most business types (including specialty retail, fast-food restaurants and sitdown restaurants) reported increases in numbers of customers per day and gross sales, except for gasoline stations and automotive repair shops, which reported decreases in the numbers of customers per day and gross sales.
Most adverse economic impacts were realized during the construction phase 
Employment within the corridors experienced upward trends overall, with some exceptions during construction phases.
When asked what factors were important to attracting customers, business owners generally ranked “accessibility to store” lower than customer service, product quality and product price, and ahead of store hours and distance to travel.
About 94% of business owners reported that their regular customers were at least as likely or more likely to continue patronizing their business after the median installation.
Along corridors where property values were studied, the vast majority of land values stayed the same or increased, with very few exceptions.

Eisele, W.L., W.F. Frawley, “A Methodology for Determining Economic Impacts of Raised Medians: Data Analysis on Additional Case Studies.” Research Report 3904-3, Texas Transportation Institute, College Station, Texas. October 1999.

## Iowa DOT

- Corridors with completed access management projects performed better in terms of retail sales than the surrounding communities
- Business failure rates at or below the statewide average for Iowa.
- Eighty percent of businesses reported sales at least as high after the project was in place.

**Notes:**
Iowa 1996 A statewide study of the effects of access management on business vitality 
Before and after data were collected on a series of corridor case studies. Data were collected from a variety of secondary sources, as well as opinion surveys and field investigations. Seven projects were selected for more in-depth  research, to illustrate the variety of project types, access management issues, and geographic situations across the state. 

Corridors with completed access management projects performed better in
terms of retail sales than the surrounding communities. Business failure rates along access managed corridors were at or below the statewide average for Iowa. Although this suggests that access management projects generally did not have an adverse effect on the majority of businesses, some businesses may have been negatively impacted.
Eighty percent of businesses surveyed in Iowa along access managed
corridors reported sales at least as high after the project was in place. Relatively few businesses reported sales declines associated with the access management project, although these business owners clearly felt that they were hurt by the project. The firms perceiving negative impacts were a mixture of business types.
Similarly, about 80 percent of businesses reported no customer complaints
about access to their businesses after project completion. Those businesses
that tended to report most complaints were highly oriented toward automobile traffic.
In all cases, 90-100 percent of motorists surveyed had a favorable opinion of
improvements made to roadways that involve access management.

 Iowa State University, Iowa Access Management Research and Awareness Project: Executive Summary, 1997.