STISIM Drive SDL - A - Approaching Vehicle

Display a vehicle approaching the driver from the other direction. If the driver’s vehicle comes in contact with this new vehicle, the crash sound effect will be played (if active), and a collision will be added to the driver’s collision total. Vehicles that are displayed using the A event will have a small degree of intelligence when it comes to traffic lights. If the light changes from green, and they are capable of stopping without breaking the laws of physics, the vehicle will stop at the light. When the light changes to green, the vehicles will then accelerate back up to their specified speed. Unfortunately, the vehicles are still "dumb" with respect to each other, and they do not know, or care where any of the other vehicles are located.

EVENT PARAMETERS:

PARAMETER 1:	The speed, in feet/second, of the approaching vehicle. You may also reference the approaching vehicle’s speed with respect to the driver’s speed by using a * in front of this parameter. If a * symbol appears as the first character in the parameter specification, the program will take the value of parameter 1 and add it to the current speed of the driver’s vehicle and use this as the vehicle’s speed.
PARAMETER 2:	The longitudinal distance, in feet, that the vehicle is away from the driver when the vehicle initially appears.
PARAMETER 3:	The lateral lane position, in feet, of the center of the vehicle with respect to the roadway’s dividing line. It is important to remember that if all of the lanes of traffic are in one direction, the roadway’s dividing line is defined as the left edge of the roadway. You may also reference the vehicle’s position with respect to the driver’s position by using a * in front of this parameter. If a * symbol appears as the first character in the parameter, the program will take the value of parameter 3 and add it to the current lateral position of the driver’s vehicle and use this as the vehicle’s lateral position.
PARAMETER 4:	Vehicle model type number {Vehicles}. You may assign the vehicle a random number by using the following syntax notation: *[low range]~[high range] (for example *1~8) In this case, the program will randomly choose a type number from all of the numbers between the low range number and the high range number. In the example, a number between 1 and 8 (inclusive) would be used. This parameter used to be the vehicle color, but since STISIM Drive uses predefined vehicle models, you must now choose a model instead of a color.
PARAMETERS 5-24:	Parameters 5 through 24 have been included to provide some control over how the vehicles behave. We have tried to make the vehicle behavior as generic as possible so that a wide range of scenarios can be programmed. Parameters 5 through 24 are actually grouped into 5 separate sets of parameters, 5-8, 9-12, 13-16, 17-20, and 21-24. Each of these sets describe a particular action that the vehicle will take. This allows you to control the vehicle 5 separate ways after it is initially displayed on the screen. You don’t have to use all 5 actions, any number between 1 and 5 can be used for each vehicle. Each action that you would like the vehicle to take is controlled by the following vehicle parameters: Parameters 5,9,13,17,21: Closure time, in seconds, between the driver’s vehicle and the vehicle you are controlling, this can be both positive and negative depending on the action that is desired. Positive meaning that the two vehicles are getting closure to one another, negative meaning that the vehicle’s are getting farther apart. Specifying the closure time so that the event acts as you intended is not an easy task. Since the closure times are irrespective of the locations of the 2 vehicles, you can add an additional attribute to the closure time parameter that tells STISIM Drive to only activate the closure time if the new vehicle is in front of or behind the driver’s vehicle. If the closure time parameter ends with an F, the action will only be activated when the new vehicle is in front of the driver’s vehicle and the closure time criteria is met (e.g. 10F would mean only in front of the driver’s vehicle and within 10 seconds and closing). Placing a B at the end of the closure time parameter, instructs STISIM Drive to only take action when the new vehicle is behind the driver’s vehicle. If neither a F or a B appears, STISIM Drive will activate when ever the closure time criteria is met. Parameters 6,10,14,18,22: Lateral distance that the vehicle will move, with respect to its current lateral position, in feet, positive to the interactive vehicle’s right. Like parameter 3 above, you may use the * symbol at the beginning of the parameter specification in order to reference the new lateral position of the vehicle with that of the driver’s vehicle. Parameters 7,11,15,19,23: New speed, in feet/second, that the vehicle will be traveling at the end of the transition period. Since you will be specifying a transition time, the program will perform a linear transition from the vehicle’s speed when the transition begins until it reaches the specified speed at the end of the transition period. If you specify a speed that is slower than the current vehicle speed, then the vehicle will decelerate during the transition period. As with parameter 1 above, you may use the * symbol at the beginning of the parameter specification to reference the new speed to the driver’s vehicle. Parameters: 8,12,16,20,24: The amount of time, in seconds, over which the transition will occur.

EXAMPLE:

100,A,20,1000,-6,*1~8,10,*0,20,2,5,-6,20,2

In the above event example, several different things happen. First, when the driver’s vehicle has traveled 100 feet down the road, a vehicle approaching the driver at 20 ft/sec will be displayed 1000 feet from the driver. This is specified by the 100,A,20,1000 portion of the event line. The center of the vehicle will appear -6 feet from the roadway’s dividing line. This means the vehicle will be on the other side of the lane striping. This is specified by the -6 parameter. The model type of the vehicle is specified by the *1~8 field and this tells the program to randomly choose a vehicle model type number from one of the first 8 available vehicle models. The remainder of the parameters deal with the vehicle taking some type of action. The first 4 action parameters (10,*0,20,2) tells the program to move the vehicle into the driver’s lane (*0) when the vehicles are within 10 seconds of each other. The vehicle’s speed will remain the same (20) and it will take 2 seconds for the vehicle to move completely into the driver’s lane. The second set of action parameters (5,-6,20,2) instructs the vehicle to pull back into its lane (-6) when the vehicles are within 5 seconds of each other. Once again the vehicle’s speed remains constant (20) and the action takes 2 seconds to complete. This event will require the driver to make some judgment as to whether or not they will be involved in a head on collision, and to react accordingly.

This event is generally used to present opposite direction traffic to the driver. A good use for this event is to stack a group of these vehicles together and tell the driver to make a left hand turn against the oncoming traffic.