<map lat='53.104253' lng='18.030152' zoom='10' view='0' float='right'/> Bydgoszcz is a city in northwestern Poland, with a population of 360,142 (June 2008), agglomeration more than 400 000, which makes it the 8th largest city in Poland.
North towards Gdańsk
Take a bus to Kamienna / Wyszyńskiego, which is the name of three bus stops at a big intersection in the Northeast of the city. Head northwards onto the street called Aleja Kardynała Stefana Wyszyńskiego, where you will already see an Orlen petrol station. Directly opposite of it is your hitching spot: A long turning lane with plenty of space for people to stop (leading to a street called Modrzewiowa). As of October 2019, if you use OpenStreetMap, you'll see a bus stop called Armii Krajowej - Cmentarz here; it doesn't exist anymore, hence the necessity to get to Kamienna / Wyszyńskiego first.
Southwest towards Poznań
Get to Błonie (the last stop of many buses e.g. 52, 52, 59, 62, 69, 92, N32). From there walk along the road, pass the gas station (it's pointless to catch a car here - only local traffic), go by bridge over the rail tracks and go straight for 100 m. There is a perfect spot for those people going to Szubin, Żnin or further to Poznań, Wrocław.
Southeast towards Inowrocław
You need to take bus no. 80 to the airport, then get off on the Jana Pawła II - Wąbrzeska or Jana Pawła II - Ziemska station.
East towards Toruń
To get to the point you need to take one of the buses going to the station Fordońska- Wiadukt (65, 81, 33N). Then cross the bridge over Vistula river (Most Fordoński, approximately 800 m long)and walk 500 m more close to Strzyżawa. There is a bus station and a perfect spot for hitchhikers going from Bydgoszcz to Toruń and Warsaw.
There is a good website showing you how to get from one point to another by public transport in major Polish cities (in Polish and English).