5.1 This practice provides a means for obtaining a quantitative estimate of a surface property defined as roughness using longitudinal profile measuring equipment.

5.1.1 The WPRI can be obtained from instruments which can capture high-resolution (described in X1.1.2) longitudinal profiles. The Pathway Measurement Tool (PathMet) is the only known instrument for this purpose.

5.1.2 The WPRI is stable with time because true WPRI is based on the concept of a true longitudinal profile, rather than the physical properties of a particular type of instrument.

5.2 When profiles are measured simultaneously for multiple traveled wheel tracks, the MWPRI is a better measure of wheelchair pathway surface roughness than the WPRI for either individual wheel track.

5.3 Wheelchair pathway roughness data can be useful in determining the vibration exposure experienced by a wheelchair user. (See Fig. 1.)

Note 1: The MWPRI scale is identical to the WPRI scale.

5.3.1 Vibration exposure has been linked to pain and injuries in wheelchair users and the WPRI of traveled surfaces provides the ability to quantify the vibration exposure a wheelchair user will experience when traveling that surface.3^,4

5.3.2 Knowledge of the vibration exposure a wheelchair will experience on traveled surfaces will allow steps to be taken to minimize their exposure, reducing the likelihood of pain and injury.

1.1 This practice covers the mathematical processing of longitudinal profile measurements to produce a wheelchair pathway roughness statistic called the Wheelchair Pathway Roughness Index (WPRI).

1.2 This provides a standard practice for computing and reporting an estimate of pathway roughness for sidewalks and other pedestrian surfaces.

1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.