Just to add my thoughts on cycling as a Professional Pedestrian (I - shamefully - cannot ride a bike and therefore walk everywhere!). Lights and a good lock are an absolute must. You never know when you might be travelling or where you might choose to leave your bike. There aren't many cars in central Cambridge, but plenty of pedestrians, so make sure you can be seen by them, as we don't tend to have lights on! At least once a term the police will do a spot check on cyclists without lights on the busiest thoroughfares, which should hopefully remind people! As someone who uses pavements, please don't cycle on pavements unless that's where the cycle lane is (this is definitely the case along Madingley Road).