When you are travelling anywhere that is a distance away, you should always re-check your travel arrangements on the day you travel. Many of us plan our journey in advance, routes we are going to take, the times we want to leave and expect to arrive plus any stops in between. When travelling on the roads, one accident or even a breakdown on the motorway can cause hours of delays which can be frustrating for all, especially if travelling with children.
My advice is to always check travel arrangements just prior to setting off. Check Google Maps for traffic updates to see if your route looks clear, if not and it seems to be long delays you may want to plan an alternative route. Many sat navs and map apps will automatically reroute you if they find a quicker route whilst you are travelling but you may have to make sure that this setting is switched on.