# Drive on a Greener Way: A Case Study on Navigating Cross-Regional Traffic Networks in South China
## 2 Related Works
### Route Planning for Sustainable Mobility  
Sustainable mobility is a key function in sustainable development. Route planning is one of the most useful methods of promoting sustainable mobility. The existing literature has proposed different methods for sustainable improvement from multiple perspectives that affect sustainability. These include the micro-level details associated with increasing energy consumption during the transportation process and the macro-level issues of environmental and road safety. These scenarios have different characteristics, and based on these, innovative weight setting has been carried out. In [19], GPS data are used record vehicles' trajectories in a specific road network. In addition to the vehicle perspective, the relationship between braking and the traffic environment is also analyzed through a trajectory analysis. The conclusions are that during traffic flow, the road structure increases braking times and carbon emissions, and the carbon emissions increase rapidly during the peak hours of the workday. In [20], the competitiveness of public transportation and vehicles is compared. The maturity of public facilities varies among different regions of South Korea, so competitiveness differs between public transportation and vehicles. In addition to road condition information, other traffic assistance information can impact carbon emissions. The article uses the T-map API to analyze the vehicle traffic status from temporal and spatial perspectives. The conclusion indicates that the competitiveness of public transportation is stronger during peak traffic periods and in well-equipped areas. In [21], a method is constructed to identify traffic congestion and estimate the air quality. This method is used to map the traffic environment with GPS trajectory data and road spatial data. Then, it predicts environmental data using traffic data. Finally, based on the prediction results, the shortest route that avoids congestion is found and presented as an information system. In [22], a route planning algorithm for vehicle-road coordination is constructed to address the problem of the navigation results being too concentrated for a given OD. If vehicles are concentrated on one road based on the navigation results, the road load will increase and the sustainability will be reduced. When the road load is controlled within a reasonable range, a method for optimal route planning is proposed. The result is a 23% reduction in the total travel time compared to that obtained with the Dijkstra algorithm. In [23], sustainable navigation methods are set. Considering driver safety, they analyze the relationship between travel time and rest habits. This is helpful for enhancing traffic sustainability through navigation from a safety perspective. In [24], navigation technology is used to reduce carbon emissions. Firstly, the traffic flow is predicted based on historical information, and then the predicted results are combined with the carbon emission mechanism model to calculate the carbon emission formula. Finally, the carbon emissions for route planning are calculated, contributing to the formation of intelligent transportation and smart cities. In [25], sustainable navigation methods are proposed to address the issue of inefficient stopping and turning during the navigation process. Firstly, a risk assessment is conducted for the stopping or turning of vehicles. Secondly, a spatial model is built and risk objectives are set for different areas. Finally, route planning is conducted by using the risk density as a weight. These methods reduce the energy consumption by more than 12%. In the traffic industry, there are various methods for setting dynamic targets for route planning. In [26], both dynamic and static traffic flow allocations are analyzed, and it is concluded that road congestion can affect drivers' route selection, which can then feed back into congestion issues. Differential equations were used to describe the traffic flow distribution process.