In the Road Traffic Bill it has drafted, and on which it is now soliciting comments, the ministry says such bridges must meet safety requirements and authorities need to reorganize traffic to ensure the parking areas are connected with nearby roads.
Businesses running the parking lots must get certification from competent authorities for fire safety and environmental protection.
In 2019 Hanoi city authorities had wanted to use the spaces under bridges for parking but the ministry shot down their proposal.
But with parking spaces shrinking, the city repeatedly petitioned for it, and in 2020 got approval to use four bridges for the purpose.
Many bridges in major cities across the country are already used for the purpose, albeit illegally.