## 4 Field Tests  
Field tests were implemented at the facilities of Durmazlar Machine Inc. in the city of Bursa, Turkey. When the dynamics of objects are taken into account, there are two different types of objects that can be encountered in a traffic scene: pedestrian and vehicle. These tests are carried out with two different objects with various configurations, as seen in Figure 10. The first case is a LRV on the same line, the second one is a pedestrian on the route of the vehicle and the third one is multiple pedestrians and another LRV. All of the tests are implemented while the test vehicle is at the velocity of 20 km/h. Some specific test scenarios were staged such as running pedestrian towards to test vehicle and dangerously crossing pedestrians. All of the test scenarios can be seen Table 1.  
Figure 10: Scenarios for another Light Rail Vehicle (LRV) and Pedestrian. Figure 9: There is an object in the danger zone and collision is highly probable. A stop sign appears on the screen, an alarm signal plays and automatic brakes are activated. Heading of the object can be seen with a red line and possible collision position can be seen with the red circle. In the first scenario, while the test vehicle is moving with a velocity of 20 km/h, there is another static LRV on the same line (Figure 10(a)). In terms of its position, the static vehicle is not in the danger zone and because it is not moving, it does not pose any danger to the test vehicle. On the other hand, since the test vehicle is moving with a velocity of 20 km/h, visual signals will appear as static LRV enters the danger zone. The second scenario that can be seen in Figure 10(b) is another LRV on the same line is approaching the test vehicle with a velocity of 10 km/h. At the same time, the test vehicle is proceeding with a velocity of 20 km/h. The approaching LRV enters the danger zone and its heading is towards the test vehicle. For the moment, there is no absolute probability of collision. So, only a visual signal appears on the screen for the tram driver. At this point, there is no need for an acoustic warning or brakes to activate. The third scenario is the next step of the scenario, and it can be seen in Figure 10(c). The LRV approaching the test vehicle with a velocity of 10 km/h is very close to the test vehicle. At the moment, it is not yet possible for a collision to occur in two seconds, but it can happen after this two-second time period. At this point, there is no need for automatic brakes. In the next scenario, another LRV approaching the test vehicle with a velocity of 20 km/h enters the danger zone (Figure 10(d)). There is a possibility of collision in two seconds because of its position, velocity, and heading. A visual signal appears on the screen and an acoustic warning is activated. Automatic brakes activate at this point because the tram driver does not step on the brakes and the probability of collision is very high. In Figure 10(e), the scenario shows an incident that can frequently occur in routine travels of the tram. There is an LRV with the same heading and velocity of the test vehicle. Although the other LRV is in the danger zone, its velocity and its heading are the same as the test vehicle. In such a situation, a visual signal appears on the screen to warn the tram driver, but there is no probability of a collision in a short period of time. Thus, the acoustic warning and automatic brakes are not activated.