Under an obscure law, certain employers that provide free parking must give cash to workers who don’t drive to work. The law applies to employers with 50 or more employees who are located in an area that violates air quality standards and who subsidize employee parking spaces the employer doesn’t own. But a new study from the California Legislative Analyst’s office shows that few companies even know about the law’s requirements. Covered employers must provide a cash allowance equivalent to the parking subsidy that the employer would otherwise pay to provide the employee with a parking space.