When visiting his parents, Tyler drives at an average speed of 42 km/h through urban areas, and at an average speed of 105 km/h along the motorway. His journey usually takes him 2. 5 hours. One day when there is a fog, he sets off 1 hour early and only manages to average 28 km/h in urban areas and 60 km/h on the motorway. He arrives 30 minutes late. How long was Tyler journey?