Bring a seat. Do you really want to put your convenience ahead of your child's safety.

I wouldn't bring a car seat. It's too much to carry on the plane. You can rent a car seat if you rent a car or borrow one. No big deal

I think your plan will work, but you could also rent a car seat in DC if you wanted - then you'd have it but wouldn't have to travel with it.

It's doable. One of the PPs mentioned the bus from Greenbelt to BWI. Also, the shuttle from the MARC is a big shuttle bus so no car seat needed.

We just went on a trip to Chicago and I bought a used infant seat and snap n go from some neighborhood moms on my local listserv. It cost me $50 for both the seat and snap n go and we checked it at the gate since baby sat in our laps during the flight. It's an option if you change your mind.

Anonymous wrote:Pp here;

I agree the bus / metro combo is more reliable for Greenbelt.

Another argument for bringing the seat is a plan if he gets sick - we were just on a trip without our older one's seat and she got sick. We did it know what to do if we needed urgent care (a car service with a seat picked us up and drove us to hotel). What if it's middle of night and no public transit?

If my kid is sick enough to need to be seen overnight, we are just risking it. Or calling 911.