In the end it went much more smoothly than I anticipated. I took off from Feldkirch, Austria on Saturday morning. My gear consisted of a backpack, a sports bag full of clothes and a cardboard sign with "Kiel" and a large smiley face on it. This is how it went down:

Day one​

After packing up the last of my stuff I got out of the house at 9 AM Saturday morning. The first thing I did was have breakfast in the center of Feldkirch while laying out my strategy. I would take the bus out to the edge of town to get closer to the highway access ramp, and use a cardboard sign with "Kiel" on one side and "Frankfurt" on the other. This would allow me to experiment with the efficacy of going for a far off location vs. a closer one.

I got off the bus at a stop I knew was close to the right highway. After walking for a couple of minutes I found what I thought was a good place to hitchhike. With my heart pounding I turned to face traffic, held up my sign and stuck out my thumb. Trying to maintain a natural smile and trying make eye contact with the drivers racing past, I stayed at this first location for about half an hour without so much as a single car slowing down. Mildly disheartened I decided to get closer to the highway access ramp.

After walking for another few minutes I was basically standing on the access ramp. Here I again turned to face traffic, and this time it only took 5 minutes before it happened. A car stopped.