<map lat='-36.784' lng='-73.054' zoom='10' view='0' float='right'/> Concepción is a city in Chile.
To Ruta 5
Take the Bus Number 30 (Ruta Las Playas) to get out of town towards "Penco". Yes, you can hitch-hike out of the city as well but a Micro is the best and fastest. Bernhard tried both and definitely recommend using a Microbus! (I needed 3 cars to get out of Conce and closer to the highway and for the last 10 km I took anyway the Micro because it was not worth it waiting - a ride with a Mico costs less than 1 USD/Euro.)
There will be a bridge and a huge Sign saying "Autopista de Itata". As soon as you see the green sign to "Chillan" with the ramp hit the button to get out under the bridge. The bus driver may ask you if you are sure because there is normally no bus stop. The ride takes about 10 minutes from Plaza Indepedencia. Don't miss it or ask someone or the diver to inform you when you are there! Sit on the right side of the bus.
Then walk back and go to the ramp. Walk a bit up the ramp since the cars are very, very fast when the enter the ramp. I waited always a bit up the hill so the drivers could see me all the way when they drive up the ramp. I used always a sign saying "Ruta 5" or "Santiago"
I got out this way 3 times with no waiting longer than 15 minutes.