There's no train connection yet with Jakarta Airport, but the company PT RaiLink has proposed to connect Soekarno-Hatta Airport with Manggarai station in the capital.
Car and bus
The airport is situated 20 kilometers west of Jakarta. The airport is easily accessible by rental car: the Sedyatmo toll road connects the airport with the Indonesian capital. The exit to the airport is clearly signposted.
A shuttle bus runs every hour to the large hotels in Jakarta's center. The so-called DAMRI bus takes much longer to get from the airport to Jakarta, but is cheap. This bus stops at Rawamangun, Pasar Minggu, Blok M and Gambir. There are also bus services to other places in the western part of Java, including Bogor.
Car rental Jakarta Airport
You can find counters of car rental companies in the Arrivals Hall. Only two rental companies are present at Jakarta Airport: Avis and Europcar. There's also a provider, Blue Bird, who rents out chauffeur-driven cars. You can also book a rental car in advance using the service provided by EasyTerra; they compare the rates of several providers in a single quote.
The official airport taxis are the fastest way to travel to Jakarta. You buy a ticket at a taxi kiosk which you show to the driver. There are set rates. You'll also have to pay the toll, but this is minimal. When you arrive late official taxis will no longer operate and you need to turn to the so-called black taxis. You need to be a good negotiator to get a good price.
Outside the terminal you can find short and long-term parking lots. You pay about 2,000 rupees per hour. If you want to leave your car at Jakarta Airport at night it's best to opt for the closed parking lot at the domestic terminal 1.