## 8 Conclusions and Discussion
### Conclusions  
This paper systematically reviews the research progress on non-conventional lane setting and control coordination optimization at urban road intersections. Through in-depth analysis of various non-conventional lane forms such as contraflow left-turn lanes, outside left-turn lanes, exit lanes for left-turn, and variable lanes, it summarizes the positive effects of non-conventional lanes in enhancing capacity, improving safety, and reducing delays. Research shows that non-conventional lanes, as an innovative traffic organization method, provide new ideas and approaches for solving urban traffic congestion problems. The main conclusions of this paper are as follows:  
(1) Non-conventional Lanes Have Formed a Relatively Complete Technical System and Application Framework  
Through systematic review of domestic and international research progress, this paper finds that non-conventional lane design has developed from early single forms to a comprehensive system containing multiple forms, including contraflow left-turn lanes,outside left-turn lanes, variable lanes, and tandem intersections. These designs realize the reconfiguration of intersection spatial-temporal resources by changing the traditional \"left-straight-right\" static layout. Research shows that non-conventional lanes can significantly enhance intersection capacity and ensure traffic safety under reasonable design. These results fully demonstrate the important value of non-conventional lanes in solving urban traffic problems. (2) Spatial-Temporal Relationship Reconstruction is the Theoretical Foundation of Non-conventional Lane Design  
This paper deeply analyzes the reconstruction patterns of intersection traffic spatial-temporal relationships after introducing non-conventional lanes. Research finds that the introduction of non-conventional lanes not only changes motor vehicle traffic patterns but also affects the right-of-way allocation for non-motorized vehicles and pedestrians, fundamentally changing the relationships of mixed traffic flow within intersections. This reconstruction involves the longitudinal and transverse matching of entrance and exit lanes and lane function conversion organization in the spatial dimension, signal timing optimization and traffic order reconstruction in the time dimension, and traffic conflict identification and management in the safety dimension. By establishing a mixed traffic flow right-of-way connection model, the paper reveals the impact mechanism of non-conventional lanes on the utilization efficiency of intersection spatial-temporal resources. (3) Adaptability Assessment and Dynamic Response are Key to Practical Application  
This paper constructs a multi-dimensional evaluation system including applicable condition analysis, traffic efficiency evaluation, safety assessment, and environmental and social benefits, providing a scientific basis for whether non-conventional lanes \"should be set up\". It establishes a demand-responsive lane function dynamic conversion mechanism, addressing the key issue of \"when and where to set up\". Research shows that successful implementation of non-conventional lanes requires comprehensive consideration of multiple factors such as traffic demand characteristics, geometric space constraints, and driver adaptability, and actively responds to traffic demand changes through dynamic control strategies. This transition from static design to dynamic response is an important guarantee for enhancing the practical application effect of non-conventional lanes. (4) Coordinated Optimization of Intersection Spatial-Temporal Right-of-Way is the Inevitable Choice for Enhancing System Efficiency  
Coordinated optimization of non-conventional lanes and signal control is key to maximizing system efficiency. Analysis in this paper shows that incorporating lane function configuration and signal control parameters into a unified optimization framework can achieve optimal allocation of spatial-temporal resources.