I've noticed that there is a close relationship between pronunciation and listening ability. Learners usually stress words incorrectly and when they hear the correct unstressed form, they can't recognise it.
I would recommend working on your pronunciation. The BBC Learning English Website has a program called, Tim's Pronunciation Workshop.
After you have learnt different features of pronunciation, I would recommend that you take an audio with a transcript and listen for all the pronunciation features that you have learnt. Then listen with the transcript. You can also do shadowing, listening, stopping, and repeating. These activities will give you a lot more attention to detail.
A great audio with a transcript is a program in BBC Learning English called Six Minute English. Each lesson teaches you 6 new words and allows you to download the audio too.
Another tip would be to listen to different types of English. Listen to monologues (one main person speaking), like in the news. Listen to dialogues between 2 or more people. Watch movies so that you get accustomed to different levels of formality and contexts.
The last tip would be to make the most of your time travelling. You can use this time to listen to podcasts, music, and lessons from BBC Learning English.