Being in a taxi in your dream or vision tells you that you are unlikely to be able to move forward in a situation, obstacle or problem without the help of others, and so you are required to ask for or take help. Another explanation is that it is not yet good weather where you want to go in life and / or the situation you are in - exploring your inner life path or journey you are making.
An important explanation is the reflection of progress in life. The explanation is the same as with a car, the journey you have to make, the possibilities, opportunities, developments, the road you want to take in your life.
If the taxi driver does not know the way in the dream or vision, this tells you that you are wandering, you do not yet know where to find the right destination. You are not finished with outlining your life purpose or wishes. You must remember that you always project yourself onto the driver; you yourself are the person who does not know the life (inner) way.
An alternative explanation is that you are guided by people with a different vision or purpose in life. You can also think of other beliefs, wishes, thoughts, habits, soul connections and like-minded. Another explanation is that you are seeking, let go of the old and want to allow new things into your life - it reflects your life journey.
Are you a taxi driver in a dream or vision then it tells you that you are helpful to others, but watch your limits. Another explanation is that you yourself can determine the future, or the way, the free will in achieving your dreams and wishes and ideas in your life. You must not forget that you always project yourself onto the driver, you are the person who knows the way.