This provides Bangladesh with a unique opportunity. You can skip the mistakes of the last 70 years regarding car ownership and transportation. Focus on making roads for buses, rickshaws and trams, trains, and even state run taxis (put the drivers on a salary). Try to build based around public transport, keep it dirt cheap and completely integrated, so that anyone who wants to travel, will much more likely do it via public transport than by car.
It is greener and long term cheaper for your country.