Have a look at www.evacmod.net , you have there many resources on evacuation modelling. The list of models on the market is here: http://www.evacmod.net/?q=node/5 and you have the results of a survey on the most known and used software here: http://64.186.156.50/~evacmodnet/?q=node/2574
If you find agent based modeling interesting, you may consider Netlogo. I think its worth a try! you can find good documentations and active support groups for Netlogo. Repast and Jade may not be a good head start if you are new to programming, specially Java.
Thank you all for your suggestions. The evacuation models I would like to implement (for example, case of Kathmandu – the Capital City of Nepal) is mainly the transit-based together with car based evacuees in multi-model network flows, incoperated with allowed lane-reversal road structure. Your suggestions and mutual interest is always appreciated.