July 26, 1990 was a beautiful day on the South Lawn of the White House. Thousands of people gathered to witness history; President George H.W. Bush was signing into law landmark civil rights legislation to protect more than 43 million Americans.

As we celebrate the 18th anniversary of the Americans with Disabilities Act, we need to ask what strides have been made to provide equal rights to people with disabilities.

According to a 2002 U.S. Census survey, the number of disabled Americans has risen to 51.2 million, 18.1 percent of the population. This makes people with disabilities the largest minority in the country.

The requirement for public accommodation in stores, movie theaters, restaurants and places where the public buys or receives goods or services began on Jan. 26, 1992, 18 months after the law was signed. Public establishments, regardless of the size of their staffs or budgets, were required to begin the process of "readily achievable barrier removal." This meant identifying the barriers that kept people with disabilities from entering as employees, customers, visitors or volunteers, and beginning to remove them.

It was intended to be a process, so if building a ramp would be too costly initially, a business might wait to include it as a "capital improvement" later and provide other means of access in the meantime. This effort was to begin in 1992 for existing facilities and to be ongoing. If renovations, alterations or new construction took place, these would have to ensure accessibility.

For eligible small businesses, the IRS offers a tax credit of 50 percent for up to $12,500 spent each year for barrier removal. The credit can be taken off the bottom line, before taxes.

But because the ADA is a complaint-driven law, many businesses have taken the I'm-not-going-to-do-anything-until-I-have-to approach, triggering investigations from the Department of Justice and myriad lawsuits from individuals with disabilities and the groups that represent them.

A number of these lawsuits have drawn criticism from commercial interests and members of the media, who ask, "Why don't people warn these businesses before they file lawsuits?"

Well, Congress empowered people with disabilities to enforce the ADA, along with the Justice Department and the courts, and Jan. 26, 1992 was the notification date. One might more reasonably ask why, 18 years after notification, so many businesses have not heeded the law's requirements.

Many believe common myths about the ADA and people with disabilities:

• 1) "My building was built before the ADA, so I'm 'grandfathered in.' "

The ADA does not grandfather any structures built prior to 1990. Existing buildings were to begin "readily achievable barrier removal" in 1992.

• 2) "I've never had someone in a wheelchair in my store (when the store has steps up to the entrance)."

Having any kind of "change in level" that is greater than a half inch (anything you have to lift your foot to get over) is a barrier to someone in a wheelchair, or someone using a walker or someone who has trouble walking.

• 3) "People with disabilities don't have much money to spend, so what is the return on my investment for making these changes to my building?"

Many businesses are unaware of the spending power of people with disabilities. According to the U.S. Department of Labor, people with disabilities have $175 billion in discretionary income, four times the spending power of tweens (8- to 14-year-olds). An Open Doors Organization study estimated in 2003 that diners with disabilities spent $35 billion in restaurants that year. More than the average likely is spent in southwestern Pennsylvania, by the way, given its high percentage of seniors.

As baby boomers age, more and more seniors will become disabled as ailments and the natural course of aging challenge their bodies. They will seek out level entrances, wide automatic doors and single-level living as they try to avoid stairs and revolving doors. Surprisingly, families with young children also seek these features. When all these people with money demand easy access to the businesses they patronize, the market will begin to change.

Making commercial enterprises accessible to people with disabilities is smart business. The ADA is a civil rights law. Not being able to eat out with family or friends, or not being able to use a restroom after a meal, is not equal treatment. When people with disabilities cannot buy goods in a store or go to the movies, it is a loss both for them and for the businesses they otherwise would patronize. Such problems also can turn into a costly and lengthy litigation.

Businesses should invest in making sure all customers feel welcome. They can take advantage of the IRS tax credit and improve their bottom line. This can be a win-w in for everyone.

As they said in "Field of Dreams," "If you build it, they will come."