Quick drives to work are very much taken for granted in most Montana communities, but such is not the case in many areas of the US.

More than one in five workers in major American metropolitan areas have quit their jobs in recent years because of unbearable commutes, according to a new survey from the Robert Half staffing company.

Research by the Menlo Park, Calif., firm shows that cities such as Denver and Miami are feeling growing pains as commutes to work become more challenging. Denver was among four cities with the largest numbers of professionals who say their commutes have deteriorated since 2013, while Miami had one of the highest levels of employee resignations due to dissatisfaction with the commute.

“Commutes can have a major impact on morale and, ultimately, an employee’s decision to stay with or leave a job,” said Paul McDonald, Robert Half’s senior executive director. “In today’s candidate-driven market, skilled workers can have multiple offers on the table. Professionals may not need to put up with a lengthy or stressful trip to the office if there are better options available.”

Men and younger workers are the most likely to give notice due to a dissatisfaction with their commutes, according to the survey, which covered 2,800 employees nationwide who are 18 or older.

Researchers have also found that employers may now have a tendency to display what’s known as commuter bias during the hiring process.

“If you live far from the job, there’s a bias against you being able to get the job,” said a researcher.