Transit workers should be allowed to strike just like any other organized labor group. If the management does not provide adequate pay and benefits to the workers, it is their right to walk out. The high demand for public transportation usually ensures that strikes are short lived and the matter is resolved quickly.
Transit workers can strike. At the same time, they can be fired, too. If their jobs were less secure, then they would not be striking. This might be considered oppression, but there are enough unemployed citizens around the country to replace all the vacant transit jobs that are going to get posted after the strikers are striked off a payroll.
Society is too dependent on transit workers to allow strikes. The ability to strike would give the workers too much leverages. The situation is similar to other essential services such as police, fire and military personnel. If conditions are bad, transit workers can just leave the sector. Limiting a prohibition on strikes to certain essential sectors ensures that workers should have the ability to work where they have the right to strike if they so choose.