About 80 percent of New York City’s street curbs are not in line with federal standards for the disabled, as first reported by DNAinfo.

A recent study by a federal court monitor revealed that even after $243 million in taxpayer funds over the last 15 years were allocated to build curb cuts, the city failed to keep them up to the Americans With Disabilities (ADA) regulations. Curb cut, or curb ramp, is the term for a ramp created by grading down a sidewalk to meet the surface of the adjoining street.

There are 116,530 ramps across the city; some were built to ADA standards but never maintained while around 4,431 curbs were simply built without ramps.

Special Master Robert L. Burgdorf, who is also the original author of the ADA Act of 1990, blamed the city’s 2002 settlement with the Eastern Paralyzed Veterans Association. In a report he submitted to federal court, he noted that the settlement did not set up any timelines for building curb cuts, nor did it require ADA compliance for curb cuts.

“It is quite plausible that the 2002 stipulation may actually have slowed down progress in achieving accessibility of the curb ramps of New York City,” he wrote in the report.

According to Burgdorf, the city only built 198 ramps in 2016, down from 6,667 ramps in 2002.

The Department of Transportation (DOT) responded by saying it increased the budget—$800 million over the next 10 years—for inspection and construction of these ramps. “As the nation’s largest municipal transportation agency, NYC DOT takes its responsibilities under the Americans with Disabilities Act (ADA) very seriously,” Scott Gastel, a DOT spokesperson, said to DNAinfo.

Burgdorf’s report recommended that the city survey all curbs within 90 days, install ADA-compliant ramps for the curbs without them in five years, and repair all of the noncompliant ramps within eight years. However, city officials estimate that it could take another 20 years before all curbs are brought up to standard,