What is the fastest way to get to Udon Thani airport from Vientiane without taking a bus?

I got a bus from the border, Thai side. On the left as walking out. I remember the bus was either Nok Air branded or the seats were! Was about 6 months ago. Hope that helps.

Taxi to the bridge and taxi on the Thai side 900 Baht to the airport from the Thai side

I went there in January. Here's how it worked out for me. Took it from a report, I wrote before.

I picked up my passport at around 3.30pm. The queue was already at number 570, so I got my passport immediately. Outside of the embassy I took a van to the border for 200 Baht (50‘000 KIP). At the border I had to pay a fee of 11‘000 KIP, because it was after 4pm. This counter is before immigration (today it was hidden by umbrellas) and you will get a card that you will need behind immigration. Laos Immigration was quick. Behind immigration I was offered a taxi to Udon Thani airport for 1‘500 Baht. I asked for a van and they said, I could sit down and wait. I opted to take the shuttle bus for 4’000 KIP (20 Baht) and to go through Thai immigration first. Took about 40 minutes to go through there. If possible, have a Thai arrival card already prepared, so you can save some time in the queue. After immigration I could hop on a van that had one seat left. It took about 1.5 hours to the airport. Udon Thani airport doesn’t have much to offer. There’s one local restaurant in Terminal A and some fast food in Terminal B.

I know when I picked up my passport from the thai consulate in Vientiane in the afternoon, made my way to the border I was able to get a taxi to take me (and a couple other people who also needed to go) to the Udon Airport to catch the 6PM flight back to bangkok without any problem at all.

take a car! i mean taxi right at Lao border

Interested to know this as well