Karlsruhe has an excellent system of public transport options. The primary one in the city centre (the city centre in Karlsruhe covers normally the districts: Oststadt, Innenstadt, (Süd-)Weststadt, Weststadt, Südstadt) is the tram system that connects most of Karlsruhe districts and some surrounding towns.
While Karlsruhe has an excellent tram system taking the bicycle is the more popular option and Karlsruhe is known as one of the most bicycle friendly cities in Germany. Using the bicycle allows you to be faster and reach destinations that are not directly accessible by the tram system.
Tram
The tram network is operated by KVV and is extended by buses to some remote districts of the city. As long as you stay in the city center you normally find the next tram stop just a few walking minutes from your location. The tram map can be found at [1].
The closes tram stop from the conference venue is “KIT Campus Süd/Durlacher Tor” and is just 3 walking minutes from the main venue. The venue for the workshops and non-core days is a further 10 minutes walk from the primary venue.
A one-way tram ticket is 2.40€ (1.80€ with a DB BahnCard) as you always need at least a 2-Waben/Karlsruhe-City ticket. You can also buy 4 tickets in one which costs 9.50€ (no savings with a BahnCard and therefore more expensive). A whole day ticket is 6.20€ for one person or 10.10€ for up to 5 person. You can find all the prices also on the KVV website.
The ticket machines on the trains only accept cash or Geldkarte (a German micro payment system). So it is advisable to either carry cash–which is a generally good idea in Germany–or to buy tickets in advance at one of the ticket machines at stations as these accept debit and credit cards.
Be advised that there is some scheduled maintenance work during the conference causing detours on the tram network. The detours mainly affect the Weststadt and a short part in Oststadt. Tram line 5 will not be operating during the conference days.
Bicycle
Karlsruhe is famous for its bicycle friendliness with Karl Drais having invented the precursor to the modern bike in Karlsruhe. The city center of Karlsruhe is absolutely flat and has a lot of special bicycles lanes and roads. Additionally many one-way streets are free for bicycles in both ways.
Normally you can reach any point in the city center by bike in less than 15 minutes and you will normally easily beat the tram and other forms of transportation. However keep in mind that you should respect all traffic regulations and not do everything local people do. Especially in the morning and afternoon traffic cyclists are known to drive like crazy. Also keep always in mind that nearly always the tram has right of way.
There is a renting service for bicycles in the city called “Fächerrrad” that costs 1€ for 30 minutes and allows you to drop your bike on any visible(!!!) corner in the city centre. Check their map for the area considered city centre in their definition. You need to register on their website and might need access to the internet to rent a bike. You might be able to use the free city internet (registration necessary) as long as you are in range or the university network (you’ll get an access code with your badge).