Extracted text: Assume you are an observer standing at a point along a three-lane roadway. AlIl vehicles in lane 1 are traveling at 48 kph, all vehicles in lane 2 are traveling at 72 kph, and all vehicles in lane 3 are traveling at 97 kph. There is also a constant spacing of 75 m between vehicles. If you collect spot speed data for all vehicles as they cross your observation point, for 30 minutes, what will be the time-mean speed and space-mean speed for this traffic stream?