Over here DonP, Sadly we have a litany of factors that cause the traffic to be hazardous.
To me, the primary cause is the flaw in our present day citizens. Sadly we are a society of selfish shipheads who refuse to be mindful of putting the needs of anyone else but themselves in their minds in their day to day lives let alone once getting behind the wheels of their vehicles. The rules I learned of safely using defensive driving has long been lost by today's drivers as a good proportion are OFFENSIVE drivers instead.
Now we have to contend with distracted drivers being a hazard as well and in greater numbers. Between cell phones, make up applying, GPS following, and just plain not planning trips wisely before setting out, distracted driving causes untold numbers of avoidable accidents.