Disclosure, bioanthro grad student not an Irish historian but I have an interest in The Troubles and I did a lot of undergrad work in cultural anthro on life during The Troubles.

The Troubles have often been seen in the popular imagination as a insurgency similar to that in Afghanistan or Iraq. In truth, the Troubles were more of a low grade insurgency punctuated by intense spikes of violence. The early years in the 1970s were the deadliest, with events like Bloody Sunday (14 dead) and the Dublin and Monaghan bombings (34) dead, but the conflict petered out often. There would be a large number of flare ups. Oftentimes one killing or event precipitated another. Five Catholics were shot in revenge for the Enniskillen bombing.

But for most people life went on as normal. They still went to the store to get milk and cheese, they still went to the bar. Roadblocks were a relatively common feature, both on the part of the IRA and British security forces. I'm unsure what chance a normal person would have of encountering a roadblock.

One of the most notable changes was the removal of public wastebins due to IRA attacks. The IRA had been using them to conceal bombs in public places like shopping districts.

The most enduring legacy of the Troubles in regards to policing is the Police Service of Northern Ireland. PSNI was brought into existence because of the Good Friday Agreement. The Royal Ulster Constabulary had a controversial reputation dating to the onset of the Troubles. Part of reconciliation was getting all the political parties in Ireland to support the PSNI, which happened in 2007 with the St. Andrews Agreement. In contrast to other UK and Irish Police the PSNI are always armed, this dates to 1970s-1990s when a large number of officers were shot and killed.

Hope that helps until a specialist can answer.