Office of Planning, Environment, & Realty (HEP)
Environment
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Sidewalk planners and designers need an objective method to assess the conditions of sidewalks. With such information, sidewalk professionals can evaluate conditions experienced by pedestrians in the public right-of-way and identify sites requiring accessibility and maintenance improvements. The information can also be used to develop transition plans, verify compliance with design guidelines, provide information to pedestrians, and continue improving sidewalk conditions for all users.
Inventorying the existing pedestrian facilities and assessing the accessibility of the travelway is the first step towards providing access for all pedestrians. Objective data obtained from sidewalk assessments enables managers to create signs and other informational guides that will assist users in selecting the best routes for travel. Conducting sidewalk assessments is also beneficial because they allow managers to inventory sidewalk conditions and plan for projects, in order to:
Figure 11-2. SWAP measures the best path of travel across a driveway crossing, as well as the cross slope of the driveway crossing on the street side of the best path of travel. This provides important information about whether the driveway crossing has a cross slope that will be detectable by people with vision impairments.
The Sidewalk Assessment Process (SWAP) is a prototype system developed to inventory the dimensions, locations, and conditions experienced by pedestrians in the public right-of-way in a reliable, consistent, and comprehensive manner. Measurement techniques from the Universal Trail Assessment Process (Chapter 12) were modified and adapted to record sidewalk conditions.
Pedestrian coordinators, sidewalk designers, and ADA experts were enlisted to ensure that the Sidewalk Assessment Process accurately recorded information in a usable format about all sidewalk features and dimensions affecting pedestrian access. Conditions identified in accessibility guidelines, pedestrian facility guidelines, and municipal transportation planning documents were also used. The terminology and measurement procedures for the SWAP were developed to ensure consistency in assessments.
Quick measurements of sidewalk components that impact access are recorded on a Stroll Sheet, which contains Station, Features, and Curb Ramp forms. Intersections are evaluated using the Intersection Checklist. Complex sidewalk elements such as curb ramps, driveway crossings, and medians identified on the Stroll Sheet are measured in more detail and recorded on the Sidewalk Element Analysis form. A complete set of the Sidewalk Assessment Process forms is contained in Appendix A.
The Sidewalk Assessment Process is intended to be a modular system. Transportation agencies should identify the components that are most appropriate to their assessment needs. For example, if an agency wanted to determine where access improvements are needed, they would use the basic evaluation recorded on the Stroll Sheet. However, if an agency has already determined that a driveway crossing is problematic, they would conduct a complete evaluation using the Sidewalk Element Analysis form for driveway crossings.
During the development of the Sidewalk Assessment Process, the following characteristics were identified to be most critical to sidewalk access:
General information about these characteristics including type, dimensions, and location with respect to other sidewalk elements are recorded on the Stroll Sheet.
The following complex elements are measured in more detail on the Element Analysis forms:
Inexpensive and easy-to-use tools have been selected to simplify the process of measuring sidewalk access characteristics. The tool kit should include a rolatape, tape measure, clinometer, inclinometer, and profile gauge. It is recommended that the assessment team wear safety vests to increase their visibility to motorists. A brief description of each tool follows:
Stations are established as reference points along the block for taking sidewalk measurements. The rolatape measures the length of the sidewalk between stations. The distance of each station is recorded on the Station Measurements form that is contained within the Stroll Sheet. Stations are established frequently to increase the number of data points and ensure a higher degree of accuracy.
The first station along each block is established 2.030 m (80 in) from the curb edge of the intersection at an area not considered part of a curb ramp (such as flares and landing). Establishing a station directly at the corner is avoided to prevent atypical measurements created by the presence of a curb ramp and to exclude the corner from the average grade measurement and calculation because the corner is generally more level than the rest of the sidewalk. Subsequent stations are established at regular intervals no greater than 50 m (164 ft) apart. The last station along a block is established approximately 2.030 m (80 in) from the edge of the intersection at a point not considered part of a curb ramp. Stations should not be established at a point considered part of a driveway crossing; instead, the station is set up before or after the driveway crossing. This is also done to exclude the generally level section of the driveway crossing from decreasing the average grade calculation of the sidewalk. It also prevents poorly designed driveway crossings with steep cross slopes from impacting the average cross slope calculations.
Sidewalk design width, cross slope, and running grade between stations are measured at each station and recorded in the Station Measurements form. Only the portions of the sidewalk that are available for travel are included in width measurements; elements such as grass planting strips should not be measured.
The measurements for features encountered between stations are recorded on the Feature Measurements form, which is part of the Stroll Sheet. A standard set of abbreviations is used to identify the type of feature. The distance to each feature, its dimensions, and any comments are recorded.
Figure 11-9. This illustration contains two features that might be located on the sidewalk and would be recorded the Feature Measurement Form. The first feature is a driveway crossing that creates a significant cross slope for pedestrians; both the cross slope and change of cross slope would be recorded. The second feature is a sidewalk crack which would be recorded as a change in level and would be measured using the profile gauge.
Aspects of curb ramps critical for determining whether or not a ramp is accessible are recorded on the Curb Ramp Measurements form, which is part of the Stroll Sheet. If information is recorded during the stroll that identifies a major element of a curb ramp should be replaced, the curb ramp is reevaluated using the Curb Ramp Element Analysis form. Both the Stroll Sheet and the Element Analysis forms capture information to determine how the curb ramp can be retrofitted. The following curb ramp characteristics are recorded on the Stroll Sheet between stations:
Figure 11-11. Some curb ramp measurements are recorded as part of the Stroll Sheet. More detailed measurements for curb ramps are recorded using the Element Analysis Form. As part of the stroll, the slope of the ramp, the slope of the roadway approach, the length of the ramp, and the length of the landing are all be recorded. If the ramp slope is less than 8.3 percent, the length of the ramp should not be measured.
The conditions at an intersection are a key factor in determining how usable the pedestrian network is for people with disabilities. If renovations are planned for an intersection, engineers should use the Intersection Checklist that is available as part of the SWAP to identify areas that need improvement. The Intersection Checklist consists of a brief series of questions that focus on the availability of information to assist in safe crossings. Most of the questions on the checklist are recorded as "yes" or "no" to allow the assessment team to quickly evaluate the intersection. Evaluators are also encouraged to sketch a map of the intersection at the bottom of the checklist to facilitate future evaluations of the same site.
Figure 11-12. The Intersection Checklist allows an assessment team to quickly evaluate an intersection based on the availability of accessible information and the probability of a safe crossing for people with disabilities.
The primary street is defined on the checklist as the street from which the assessment team approached the intersection; the cross street is defined as the street perpendicular to the primary street. The total number of lanes and the crossing distance are recorded for both the primary street and the cross street. The presence of traffic signals, stop signs, parked cars, medians, and marked crosswalks are recorded to gain a better understanding of how difficult the intersection would be to cross for people with slower walking speeds. The length of the walk interval is also recorded if a pedestrian signal is located at the corner. The accessibility of pedestrian actuated control signals and the patterns of right and left turning automobiles are recorded to evaluate the information available to people with vision impairments. The sound of automobile traffic is another important cue used by people with vision impairments at intersections; however, the presence of traffic is not recorded because it often fluctuates based on a variety of factors including the time of day and the weather conditions at the intersection. Additional intersection observations should be recorded as comments at the bottom of the checklist. Signal types, timing, and crosswalk configuration all affect usability of a pedestrian route. TEA-21 requires consideration of accessible (audible and vibrotactile) pedestrian signals.
Sidewalk Element Analysis Forms are used to record information about complex sidewalk elements, such as medians and curb ramps, that are identified by the Stroll Sheet measurements as warranting further evaluation. Depending on the element being evaluated, dimensions are recorded on forms depicting schematic diagrams of:
A complete set of Sidewalk Element Analysis forms is included in Appendix A. The following example reviews the Driveway Crossing Sidewalk Element Analysis form. To completely analyze a driveway crossing, each of the following measurements are recorded. Some of the measurements explained below may not be applicable to every complex element. Furthermore, some additional measurements that are not applicable to driveway crossings may be recorded for some of the other complex elements. For example, the location of a detectable warning would be recorded for a curb ramp but is not recorded for driveway crossings.
The SWAP is a tool that produces valuable data and may assist designers and planners to make targeted access improvements to bring their communities into compliance with the ADA. Sidewalk assessment data can also be used to create useful information for pedestrians. The following ideas are based on Universal Trail Assessment Process products, such as the Trail Access Information strip, and have not yet been developed for sidewalks. Additional information about Universal Trail Assessment Products is contained in Section 12.5. The following information formats should be considered for future development because they would benefit many sidewalk users:
Figure 11-20. This type of sign has been used in trail settings. Pedestrians could benefit from objective information about sidewalk conditions, such as steep grades and cross slopes.
