Happens pretty frequently.Yes a main reason for delays is a broken down bus.
Another is construction and detours that ensues.
A bus driver taking a break then forgetting where he left off is another reason.
Unruly,inebriated passengers is another reason.Needing an emergency response team for aforementioned drunk and or a fall can and will cause the bus to be late.
Holidays ! Yes Holidays and summer weeks of new drivers learning a route and supervisors on vacation

At times traffic or other issues can cause delays in service. Please report specifics to Customer Service at http://www.cttransit.com/Contact/FeedbackForm.asp or by calling 230-624-0151.