- Airports: Total number of airports. Runways must be useable, but may be unpaved. May not have facilities for refuelling, maintenance, or air traffic control.
- Airports > Per capita: Total number of airports. Runways must be useable, but may be unpaved. May not have facilities for refuelling, maintenance, or air traffic control. Per capita figures expressed per 1 million population.
- Gross value added by transport, storage and communication: Gross Value Added by Kind of Economic Activity at current prices - US dollars.
- Highways > Total > Per capita: total length of the highway system Per capita figures expressed per 1,000 population.
- Motor vehicles: Motor vehicles per 1,000 people
- Motor vehicles > Per 1,000 people: Motor vehicles include cars, buses, and freight vehicles but do not include two-wheelers. Population refers to midyear population in the year for which data are available."
- Passenger cars > Per 1,000 people: Passenger cars refer to road motor vehicles, other than two-wheelers, intended for the carriage of passengers and designed to seat no more than nine people (including the driver)."
- Ports and terminals: This entry lists major ports and terminals primarily on the basis of the amount of cargo tonnage shipped through the facilities on an annual basis. In some instances, the number of containers handled or ship visits were also considered.
- Rail > Railway length: Railway length in kilometers.
Road > Motor vehicles per 1000 people:
Motor vehicles per 1000 people.
No date was available from the Wikipedia article, so we used the date of retrieval.
- Road > Motorway density: Meters of motorway per square kilometer.
- Road > Motorway length: Total network length of all motorways in km.
- Road network length > Km: Length of road network in kilometers in European Union countries.
- Roads > Passenger cars > Per 1,000 people: Passenger cars (per 1,000 people). Passenger cars refer to road motor vehicles, other than two-wheelers, intended for the carriage of passengers and designed to seat no more than nine people (including the driver).
- Roadways > Unpaved: This entry gives the total length of the road network and includes the length of the paved and unpaved portions.
SOURCES: CIA World Factbooks 18 December 2003 to 28 March 2011; United Nations Statistics Division; All CIA World Factbooks 18 December 2003 to 18 December 2008; United Nations World Statistics Pocketbook and Statistical Yearbook; International Road Federation, World Road Statistics and data files.; Wikipedia: List of countries by rail transport network size (Long List); Wikipedia: List of countries by vehicles per capita; https://www.cia.gov/library/publications/the-world-factbook/fields/2085.html, Roadways.
- El Salvador ranked #5 for airports amongst Densely populated countries in 2013.
- El Salvador ranked first for vehicle abundance amongst Former Spanish colonies in 2001.