In terms of road safety Italy can be considered as a fairly safe place. That is also proven by the various statistics on the subject, e.g. those published by OECD.
However, if we talk about cycling safety specifically that is a slightly different case. If you usually cycle in Germany, or maybe in Belgium or Holland, where there are much more dedicated cycle ways then you might find Italy slightly more demanding. However, if you ask me, as someone with a totally subjective opinion cycling in Italy is not much worse or too different to cycling in England or France for example.
As we all know, the more cyclists and cars on the road the more chance for an accident. That is quite obvious. The vast majority of cycling accidents happen in busy towns and cities. If you are not too confident then try to avoid those (of course in peak times!) and concentrate more on quite country roads to reduce risk. There are also plenty of traffic-free cycle ways to choose from which is another thing to consider.
With regards to my own experience Italian drivers are not as bad as people would think. If there is enough space on the road then they will try to be careful and give you enough space too. Of course doing so on a narrow city street is a bit of a challenge so it is important to be careful by all means.
Motorcyclists are also okay usually, but – as Italy is also a popular destination for them – the surroundings of the well-known tourist attractions can be quite crowded on hot summer weekends. Again, most of the motorcyclists would normally pay attention to those also on the street, but unfortunately there might be one or two exceptions.
There are also bad habits in Italy – just like in the UK or elsewhere – that we should mention briefly. Throwing rubbish out of the car’s window while driving, using a mobile phone – unfortunately these still happen, even though the latter is definitely illegal. There are also those situations where one driver quickly decides to overtake the other who is slightly slower, without necessarily considering the cyclist who is also nearby. So you should keep those possible risks in mind while touring in Italy.
To sum it up, Italy is not so much different to any other countries in Europe in terms of cycling safety. Wearing safety helmets, high visibility vests, appropriate lights or reflectors, sunglasses etc. is inevitable if you are going for a longer trip. If you have those, and also keep the above information in mind then you probably do a lot to reduce the risks and you will have a good chance to have a great time in Italy.