Trains are actually the most comfortable and safe for longer travel because you can stretch your legs. For daily local commute, auto-rickshaws are okay if the roads aren't bumpy, but tell the driver to go slowly. Metro is also a great option if you get a seat.
For my daily office commute, I preferred the metro or a cab over local buses to save time and energy. If driving a car, make sure the seatbelt goes under your bump, not over it. Avoid traveling during peak rush hours to stay safe and comfortable.
I was so scared of traveling during my first trimester and worried every small bump would cause harm. Trains and flights are usually the safest and smoothest for long distances, and metro is good for daily commute. Just speak to your gynac once before traveling to get reassurance.
Right now in my 3rd trimester, even walking to the car feels exhausting! A comfortable car where I can recline the seat is the only way I travel now. Stay away from bikes and bumpy rickshaws unless you want your baby to bounce out lol!
Honestly, the safest mode of transport was my bed because traveling anywhere with a heavy bump felt like torture! But seriously, avoid two-wheelers and local autos on bad roads unless absolutely necessary. Metro or a comfortable car with a seatbelt is your best bet.