Transit Ridership and Access to Airports
The issue of transit access to airports is popular right now. In 1980 - or even 1990 - few American and Canadian cities had rapid transit access to their airports; now, it seems every year brings a new city adding rapid transit access to the airport. Most recently Miami joined the club with a short extension of their Metrorail system to Miami International that opened July 28, 2012. Why the focus on airports? While it may be to attract more tourists who do not want to rent cars , transit access to airports is a favorite topic for the choice rider (including transit planners) who envisions the airport as one of the few places he or she would consider taking transit to access. This article will examine transit ridership to airports and issues involved with transit access to airports.
Transit Ridership to Airports
What percentage of trips to airports are taken on public transit? By public transit I mean scheduled bus and rail service operated by the region's public operator, and not shared ride vans, privately operated airport charter service, hotel shuttles, and other similar ventures. Not surprisingly, mode share on traditional public transit is very small. About 11,000 passengers per day (about 4,000,000 per year) board BART trains at San Francisco Airport (SFO), making it the American airport with the highest public transit usage. However, in 2011 SFO carried 41,000,000 passengers, making for a public transit mode share of a little less than 10%. Many American airports have effective transit mode shares of 0%, including touristy places such as Las Vegas and Orlando as well as airports in ex-urban areas like Dallas / Fort Worth.
Who rides transit to airports? While many would believe that it is airline passengers that make the most trips on airport transit lines, it is actually airport employees who use airport transit the most. For example, a 2005 survey of passengers on San Diego's airport public bus route showed that 65% of passengers worked at the airport while 35% were flying from the airport. In some cases, fare policies prevent the usage of airport transit lines by airport employees. For example, the surcharge that BART adds on trips beginning or ending at SFO has caused the airport to operate an employee shuttle from the next nearest station - Milbrae. Milbrae Station does not have any fare surcharges.
Designing Airport Transit Lines
One of the major issues in regards to transit access to airports is in the network design : how will the airport section of the line fit in with the rest of the system? While a few cities have lines that serve the airport on the way to another destination (most notably National Airport in Washington, D.C. and Seattle / Tacoma airport), most transit corridors serving the airport terminate there, becoming either branches of a main line or a shuttle.
Why Rapid Transit Lines End at the Airport
Before we examine the branch / shuttle issue, why do very few airport lines continue past the airport to another destination? There are at least three major reasons. First, airports are generally at the end of the city - either the end of the city's built up area or the geographical end of the city. Many airports are built on water, presumably to lessen noise impacts on take off and landing as well as to improve safety in the event of accidents. The very fact that they are next to water means there are no other places for the line to go. Of course, airports that were originally built in the country can find themselves surrounded by new development - new development that the Piccadilly Underground line in London, for example, cannot serve due to its unique looping arrangement at Heathrow Airport.
Second, the vast majority of the land area of an airport is made up by runways, leaving large swaths of land with zero demand for passengers. At up to $1 billion per mile (estimated cost of New York City's Second Avenue Subway), why waste money on building track that will serve nobody?
Third, safety and (increasingly) security reasons make it difficult to construct lines in the vicinity of airports. For example, the FAA has required Los Angeles Metro to place the Crenshaw light rail line in a trench in the vicinity of LAX airport in order to avoid any possible interference with flight activities. If elevated lines are out, and since there is no room for surface rail operations at an airport, then if a line is going to penetrate into the airport proper it will have to be as a subway, which greatly increases costs. More importantly, in an era when everybody is a terrorist until proven otherwise , it is unlikely today that underground rapid transit lines will be allowed to travel directly underneath the airport terminal proper.
Network Issues Caused by Airport Transit Lines
Because the vast majority of airport rapid transit lines end at the airport, the lines must either be operated as a shuttle to the main line or as a branch of the main line. Visitors to JFK airport in New York are undoubtedly familiar with the AirTrain, which in addition to shuttling you to the other terminals and the rental car lot will take you to Jamaica or Howard Beach where connections can be made with the subway. Although the connection is pretty painless, the fact that a transfer is required likely deters airplane passengers lugging several pieces of baggage from taking transit to JFK. Visitors to YVR airport in Vancouver, B.C. experience Skytrain as a branch of the main line to Richmond. Because in a branch situation each branch has a headway equal to half of the overall frequency, the airport branch in Vancouver means that the other branch has 50% of the number of trains that it normally would receive - and this train shortage has caused overcrowding in the peak periods. At SFO it is not the airport travelers who are affected by BART's operation plan, as there is always direct service from SFO to downtown San Francisco. It is passengers destined for Milbrae Station, who evenings and Sundays have to endure a lengthy detour to the airport.