Poland is a special case. They have the highest number of traffic accidents per capita in all of Europe, 50 percent higher than the EU average. Poland doesn't follow international best practice when it comes to speed limits. You are right that speeding is the chief concern. Here's what the World Bank 2013 review of road safety in Poland says:
"Age and gender are well recognized contributors to road trauma risk. Age is a major risk factor, with a dramatic increase in risk of death and of being the driver in a fatal or injury crash, from the age of licensing (18 years in Poland) and continuing through to age 24, followed by a gradual decline in trauma risk. In Poland the highest population based fatality rates are in the 18-19 and 20-24 age groups, lowest between 40 and 59, with a gradual rise in the older age groups. "