# Analysis of Conflict Distribution Characteristics between Motor Vehicles and E-Bikes at Roundabouts
## 3 Results
### Conflicts Temporal Distribution Characteristics  
This research extracted the conflicts data that occurred in one green light period of a signal cycle. The general conflicts and serious conflicts distribution trend lines with time changing was plotted in Figure 12. The distribution of Conflict Type 1 and Conflict Type 2 at three roundabouts are shown, respectively. Figure 12: The distribution of two conflict types during one signal cycle period. (**a**) Distribution of Conflict Type 1 (Zhuque); (**b**) Distribution of Conflict Type 2 (Zhuque); (**c**) Distribution of Conflict Type 1 (Hanguang); (**d**) Distribution of Conflict Type 2 (Hanguang); (**e**) Distribution of Conflict Type 1 (Chenyangzhai); (**f**) Distribution of Conflict Type 2 (Chenyangzhai). It can be obviously seen that the changing trend of conflicts at three roundabouts all show increasing first and then decreasing. The number of general conflicts increases rapidly at the beginning period of the green time, reaches a peak at the 2 nd and 4 th ten-second interval and then decreases gradually. The peak of serious conflicts shared a similar period with general conflicts, but the increase and decrease rate is slower than general conflicts which is mainly due to the number of serious conflicts being smaller and more scattered than general conflicts. To address a general look of the conflict distribution characteristics between vehicles and e-bikes in roundabouts with time changing, in this paper we also analyzed the integrated conflicts data of three roundabouts. The 10% green time length was selected as the interval to study the overall conflicts distribution characteristics. The distribution of Conflict Type 1 is plotted in Figure 13.  
As shown in Figure 12, the distribution characteristics of Conflict Type 1 during one green time could be summarized as follows:  
1. The number of conflicts reached a peak at the 30 th percentile green time period, and then gradually decreased to zero when it reached the red light period. During the 0-10 th percentile green interval, the conflicts increased most rapidly which is mainly due to the fact that, at the green time beginning point, both right-turning vehicles that need to exit the roundabout and the e-bikes that need to continue go ahead were released together. A large number of vehicles and e-bikes entered the roundabout at the same time and formed interweaving. Before right-turning vehicles exited, as their trajectories are different with the e-bikes and the right-turning vehicles traffic flow is large, plenty of conflicts occurred at the early green time. 2. With green time moving, vehicle and e-bike traffic flow turns from sharp increasing to flat, and then the conflict growth trend goes down. 3. During yellow lights, a few conflicts, which were mainly due to some cyclists and drivers wanting to squeeze through before the red light, still exist. 4. The decreasing speed of general conflicts is faster than that of serious conflicts. This is because the number of serious conflicts is smaller, and the distribution of serious conflicts is flat and scattered, while the general conflicts show a trend of sudden increase and slow decrease. In the same way, the overall conflict distribution of Type 2 is plotted in Figure 14.  
Figure 13: Overall conflicts distribution of Type 1. The distribution characteristics of Conflict Type 2 during one green time period could be summarized as follows:  
1. The changing trend of conflicts is the same as that of Conflict Type 1. It reached a peak at the 30 th percentile green time period, and then decreased gradually. However, for Conflict Type 2, left-turning e-bikes were the main object that conflicted with vehicles, and left-turning will take more time to arrive at the conflicts area. These e-bikes may also collide with the right-turning vehicles who have occurred Conflict Type 1. Thus, conflicts in the first 10 th percentile green time period are fewer than Type 1. 2.