KARACHI, Pakistan — “Don’t look at a woman over and over again in your rearview mirror. Don’t make comments about the way they dress. Don’t ask them if they’re married.”

An impassioned young instructor, Muhammad Wahaj, was leading the day’s first training session in Karachi this fall for drivers for Pakistan’s biggest ride-hailing app, Careem, one of the start-ups trying to slowly change the way many women here go about their daily lives.

“All of this makes women feel uncomfortable, and it’s unacceptable,” he warned the 10 men. “We won’t tolerate it.”

In Pakistan, women who work outside the home have limited options for even getting to those jobs. Public transportation is abysmal, private buses are wildly overcrowded and only 3 percent of households own cars.