Transport in Thailand is varied and chaotic, with no one dominant means of transport. Bus transport dominates in long distances and Bangkok, with motorbikes dominating in rural areas for short trips, supplanting bicycles. Road transportation is the primary form of freight transport across the country. Slow rail travel has long been a rural long distance transport mechanism, though plans are underway to expand services with high speed rail lines extending to several major regions of Thailand. Domestic air transport, which until recently had been dominated by a select few air carriers, has recently seen a surge in popularity due in large part to the expanding services of low cost carriers. In Bangkok, Pattaya, and other large cities, public motorbike taxis take people door to door. An overwhelming number of taxis can also be found in Bangkok. Since the country's first rapid rail transit line opened in 1999 in Bangkok, daily ridership on Bangkok's various transit lines has risen to over 800,000, with multiple additional lines either under construction or being proposed. Private automobiles, whose rapid growth contributed to Bangkok's notorious traffic congestion over the past two decades, have risen in popularity, especially among tourists, expats, upper class and a growing middle class. A motorway network across Thailand has been gradually implemented, with motorways completed in Bangkok and most of central Thailand. Areas with navigable waterways often have boats or boat service, and many innovative means of transport exist such as tuk-tuk, vanpool, songthaew, and even elephants in rural areas.