I've commuted regularly by bicycle for almost 2 decades in 3 other countries, but were I am now - Portugal - I won't because drivers are stupidly dangerous (some of the worst in Europe judging by accident statistics), though unlike almost all of my countrymen here I refuse to buy a car and walk, use public transportation or at worst rent one when needed.

The infrastructure isn't even worse than in Britain (were I did regularly cycle to and from work): it's just that when there are no segregated cycling lanes the quality of everybody else with you on the road makes a huge difference when you're the narrow crosssection (so harder to spot for drivers who just quickly peek on the mirrors and easy to fit on their blindspot) squishy, i'll protected and low-acceleration road user.