The most towns and cities of Nepal have a Public bus park. Buses are with 16 to 25 seaters with no air conditions. Other public transportations available are Micro bus, Taxi etc.
Mostly visitors who visit to Nepal took a Tourist bus that serve Kathmandu-Pokhara-Chitwan-Lumbini. Mostly of them have a good seats with air conditions. Also you can booked cars, Jeep and vans for your tour you should book it earlier. Mostly the tourist vechiles have air condition and clean.
The domestic air transportation is very popular in Nepal. You can get a domestic flights from kathmandu to other big cities like Pokhara, Lukla, Bharatpur(Chitwan), Dhangadi, Biratnagar, etc.The are more than 10 airlines that took a flight everyday around Nepal with scenic views of white and green Mountain. The airlines like Nepal Airlines, Buddha Air , Yeti Airlines, Shree Air, Simrik Air, Guna Air, etc took flight to Pokhara,Chitwan,Dhangadi,Biratnagar which have 70-80 seater and the airlines like Summit Air, Sita Air, Tara Air and Nepal Airlines took a mountain region flight to Lukla,Jomsoom,Dolpo with 15-20 seaters.