1.1 Background of the research
At present, with the development of global economy and the rapid growth ofurban population and motor vehicles, most cities in the world are facing huge trafficproblems. Due to the rapid growth of country’s economy, the process of urbanizationis advancing rapidly and the scale is expanding day by day. Residents are alsogrowing. With the concentration of population flow to the city, the total trafficdemand increases sharply. The urban traffic problem is increasingly prominent. Themain problems are traffic congestion, high accident rate and the number of motorvehicles which cause serious air pollution. The traffic congestion in many cities isbecoming more and more serious. The main roads in the city are overloaded, thespeed is low, and the travel time of residents becomes longer. Today, with the rapiddevelopment of motorized travel, due to the imbalance of urban and rural economicdevelopment in Kazakhstan, most of the vehicles, especially private cars, are mainlyused in urban areas of the country, which brings severe challenges to urban traffic.For example, in Almaty and other big cities, these problems have become veryprominent. Although all countries in the world have taken various measures todevelop urban traffic and improve traffic efficiency, the urban traffic problem has notbeen fundamentally solved. More and more attention has been paid to urban trafficproblems by the government and urban residents .
1.2 Brief introduction of BRT
Bus Rapid Transit (BRT) system is a high-quality public transport system basedon the private right of way or priority between rail transit and general public transport.It provides a fast and reliable way for passengers to travel. At present, BRT systemhas been put into use in many cities.
According to the Energy Foundation, BRT system is a kind of public transportmode that uses advanced public transport tools and bus lanes to ensure the flexibilityof public transport and the convenience of rail transit.
According to the international traffic development policy center (ITDP), BRTsystem is a public transport mode transport system which makes use of modern publictransport technology such as its and modern operation management concept to helpthe public transport system reach the service level of rail transit .
The federal transportation administration (FTA) believes that the differencebetween the bus rapid transit system and other public transport systems is that theyfocus on the high quality of public transport services, including convenience, comfortand economy, as well as the concept of passenger oriented operation .
2 Literature Review
2.1 Brief introduction of BRT
In the literature of environment and transportation economics, roadtransportation is widely considered as one of the main sources of air pollution.According to the International Clean Transport Council (ICCT), more than 20% ofglobal carbon dioxide emissions come from the transport sector. 
Generally speaking, the literature recognizes the role of public transport inreducing carbon dioxide emissions, mainly considering that the per capita greenhousegas produced by public transport is lower than that produced by personal vehicles[11,12, 13]. The research shows that cities that give priority to sustainabledevelopment and public transport have obvious environment-friendly streets. If halfof the money spent on highway projects goes to Bus Rapid Transit the impact ofcarbon dioxide will be reduced by a quarter.
The Institute for Transport and Development Policy (ITDP) provides one of themost detailed definitions of BRT services and infrastructure. It is defined asfollows:
"Bus Rapid Transit (BRT) is a high-quality bus based transportation system thatcan provide fast, comfortable and