Last week Ms. asked me to respond to a New York Times article by David Leonhardt in which he asked why the labor market is so punishing to mothers. He notes an obvious pattern--that top posts in both the private and public sectors usually go to single or childless women—and wonders if American feminists early on focused too much on policies to eliminate blatant sexism rather than family responsibilities discrimination.

Here are some facts:

• Many more women take time off from the paid workforce;

• Many more women work part-time at some point in their lives;

• Many more women can't work extreme hours, getting to work both early and staying late;

• Our economy exacts a steep price for time away from all-encompassing, full-time, paycheck jobs.

It’s all true and we’ve heard the catch phrases to describe it: the glass ceiling, the maternal wall, and the price of motherhood. And now let’s add the price of lane changing.

In my new book, The Custom-Fit Workplace, my co-author Joan Blades and I learned that today’s workers are truly a diverse lot. Some stay in the fast-lane, some slow down for awhile and then ramp back up, and some chug along for decades.

People want to make lane changes from time-to-time during their work lives. Yet doing so exacts a price in terms of lost earnings and lost opportunities. The culprit is not the early policy choices supported by feminists. Yes, feminism pushed for equal rights and equal opportunities but also for family-friendly policies and continues to do so vigorously today.

Rather, the culprits are a leadership mindset and set of workplace policies that have not caught up with the reality today that most households consist of dual earners, that women comprise 50 percent of the labor force and 80 percent of them will become mothers, and that people live so long today they are unlikely to stay in high-gear for 50 years.

It’s not just mothers who need and want to make lane changes over the course of their work lives. More than half of men in one survey said they wanted the option to slow down their career when family demands grew. And baby boomers want to retire gradually: slowing down before fully retiring. Gen Y is not sure they want extreme jobs in the first place, but if they do they envision taking sabbaticals to recover and re-charge.

“The main barrier is the harsh price most workers pay for pursuing anything other than the old-fashioned career path," Leonhardt concludes.

Some call this the path of the “organization man” or the “ideal worker.” Whatever it’s called, today it’s an outmoded path. Some smart companies are recognizing this and establishing ongoing networking, training, and mentoring to attract people who have exited the labor force or downshifted. Some are recruiting heavily among off-ramped moms. Some are allowing career customization. Others are getting creative in the flexible work career options they design with their employees: part-time without benefit penalties, job-sharing, telecommuting, and even allowing infants at work.

The key is to find the fit that keeps each person productive and engaged, not just mothers but all others too: young, old, fast- and slow-lane, single, parents, newcomers, and veteran workers. Adaptable, entrepreneurial American companies are up to this new challenge.