A Risk-Based Approach to Managing ADA Assets

Posted August 5, 2021

There are few assets where a condition-based, “worst-first” approach to maintenance and replacement leaves a public works agency more exposed. Compliance with the Americans with Disabilities Act (ADA), Section 504 of the Rehabilitation Act is mandatory, and fines for not complying can be significant. Often, strategy documents don’t align with the in-the-field tactics of managing ADA assets like sidewalks, curb ramps, and paved roadways. These facts make a risk-based approach to managing the sidewalk and curb ramps the right process.

Risk is defined as exposure to the chance of injury or loss. Likewise, in asset management, we define risk in a similar fashion where risk = condition of an asset x consequence of failure. When it comes to ADA assets, it’s important to focus on determining the condition and consequence of failure. What makes ADA assets unique and complicated is that condition is often pass/fail and typically localized. While the consequence of failure has financial implications in the form of fines, human access implications can make activities, such as paving, cost-prohibitive due to regulations requiring ramps to comply with Section 504 of the Rehabilitation Act when upgrading pavement.

Organizations gain an understanding of ownership and maintenance responsibilities using linear referencing.

One technique that allows us to prioritize ADA assets using a risk-based approach is linear referencing. First, we must look at the ADA asset as a component of a larger network. For example, imagine a travel route a person in a wheelchair might take. To do that, we must use a GIS technique called lineal referencing; in less technical terms, we create sidewalk “routes” that correlate with roadway routes and paths of travel.

Putting your sidewalks, ramps, and crossing assets into a linear referencing system allows us to look at a “route” and aggregate ADA facilities into a more “project-based” structure. Assets in this format allow organizations to answer the following questions:

  1. Is my asset part of a larger route or network?
  2. What effect do individual assets have on the condition of the route?
  3. Would stakeholders be able to navigate this route in a wheelchair, and what is the consequence of the condition of assets along this route?
  4. Is the condition of the ADA asset going to prevent maintenance activities on neighboring assets such as street paving?
  5. How can I invest once to make the most impact?

Part of a sidewalk condition assessment tool created in Esri's Survey 1 2 3 Software.

Now that we have insights into our assets along a route using a linear referencing system, we need to weigh the conditions of individual assets along a particular route. When looking at ADA assets such as sidewalks, ramps, and crossing assets, the condition is often pass-fail. Therefore, to rank each route using a risk-based approach, we need to understand the impact of a failure. This can be highly individualized based on organizational capability, levels of service requirements, and culture. For instance, if an organization has eighty (80) ramps per mile in its downtown core, the cost of making ramps ADA compliant can make the paving cost-prohibitive. If making ramps ADA compliant is a priority, that asset class would have a high consequence of failure score. Ultimately, the condition of assets along a route equals the route’s overall risk score.

For example, inspectors would start by walking a sidewalk route and take a condition assessment on ADA Assets. Next, they would assess the ramps using Esri’s Survey 1 2 3 software using the PROWAG standard. If the ramp fails for any reason, that failure contributes to the risk score of the entire route. A spatial overlay of zoning and high priority areas might also elevate the risk score by adding to the consequence of the failure side of the equation. As inspectors walk down the route, they also track defects along the route that might affect travel, including signals and sidewalks. A ranking system should be developed in a workshop and individualized for an organization. The scoring might look like this:

  1. Risk = condition x consequence
  2. Risk Score = ((# of ramp fails x 4) + sidewalk defects + (# signal fail x 2)) x (zoning) + ((# of ramp fails x 4) + sidewalk defects + (# signal fail x 2)) x (zoning)
  3. 120 = ((3 x 4) + 4) x (6) [96] + ((1 x 4) +(1 x 2)) x (4) [24]

Variables can also be included for special areas and districts. In the end, each route gets a risk score so that maintenance and replacement activities can be ranked and prioritized using a “risk-map.”

Events happen along a route in a linear referencing system. In this case ADA Assets conditions become events along a route.

Calculations are formulated in a GIS database so that the map corresponds to the risk score of each route. Once the final categorization is made, high-risk routes are color-coded red while lower-risk routes are yellow and green, respectively. This provides organizations with the option to layer the ADA routes over street paving, water projects, or any other asset allowing for risk-based project development and maximum cost savings.;