Plenty of hotels in various price classes (45€-150€/night) are available and can be booked online at the accommodations listings at the Karlsruhe City Internet tourism site:
http://www.karlsruhe-tourismus.de/en
Karlsruhe offers a wide range of hotels to the visitor. Participants are responsible to make their own reservations.
Please mention KIT and the meeting (ST3-Workshop) when making your reservation. Because some hotels offer special KIT rates, for example, the IBIS Hotel.
http://www.accorhotels.com/gb/hotel-6965-ibis-karlsruhe-hauptbahnhof/index.shtml
A transfer by car or bus is planned with pick up at the main train station “Karlsruhe Hauptbahnhof”.
Other hotels near main train station:
Schlosshotel Karlsruhe http://www.schlosshotelkarlsruhe.de/en.html
A&O Hotel http://www.aohostels.com/en/karlsruhe/
Avisa Hotel http://www.hotel-avisa.de/