These graphs present data on the types of transportation that commuters use to travel to their workplaces in Houston, Texas.
Overall, cars with just one driver are the most common vehicle to work and also cause more pollution than other means of transport.
Cars with only one person account for the highest proportion at 48 percent, and the average age of these commuters is 43 years old. Trains and buses are the second most common, used by 37 percent of workers. The average old age of bus and train passengers is 47. People who carpool have an average age of 44, slighty lower than bus and train commuters. However, only 11 % of the traveller choose to carpool. Also, just 4 percent of people walk and cycle to work, and their average age is 39 years old.
Among all the forms of transport, cars with one person emit over 0.3 kilograms of carbon dioxide per kilometre. Incomparison, cars with multiple occupants emit just under 0.1 kilograms per person per kilometre. Buses and trains are emitting less than 0.05 kilograms CO2 per person per kilometres. Cycling and walking are the greenest options, producing mostly no CO2 into the atmosphere.