edwin_m
Veteran Member
From the post with the chart:I presume the chart takes into account average load factors (Megabus is efficient because it is pre-booked and so the average occupancy is higher than the service busses also on the chart). This means the private car will contain more than one person to achieve the quoted efficiency. Drive alone and your mileage is probably worse than the plane.
Data assumes the following load factors: urban bus 20%, intercity coach 60%, intercity rail 40%, all other trains 30%, domestic airlines 70%, and cars 30%. Road, air and diesel-powered rail vehicles’ emissions have been increased to take account of refinery losses and electric powered vehicles take into account losses in the grid.
These figures are probably percentage of seats occupied (but could be percentage of total seats plus standing space, but this uncertainty doesn't affect the car figures). Most cars have 4 seats, a few have several more and some have only 2, but the average is probably around 5. This would make the 30% equal to 1.5 people per car, which is about what surveys normally give.
A whole new can of statistical worms is opened if you consider people collecting and dropping off. For example collecting a student from college might involve a parent driving alone from home to college and returning with the student. But if the student had taken public transport both those journeys would have been avoided.