Defining ALC model parameters

Note: You must have an automotive license.

For the Decision model for lane changes in Vissim (Operation of the Adaptive Cruise Control (ACC) vehicle following model) you can show and define the following parameters and their values in the Driving Behavior list:

Parameters	Description
ALC_a_d_r_acc	Maximum allowed deceleration that may be required by the trailing vehicle on the destination lane if the lane change is performed.
ALC_a_d_r_cancel	Maximum negative acceleration that may be required by the trailing vehicle on the adjacent lane. If stronger braking is predicted, the ego vehicle will stop the lane change process.
ALC_beta	If the lane change should be aborted, it will only be aborted if the distance to the lead vehicle is sufficiently large. ALC_beta describes how much smaller this distance can be compared to the normal distance.
ALC_delta_v_limit	Speed difference to the maximum speed defined in the 'ALC_v_limit' attribute of the lane. The ego vehicle assumes that when changing to the adjacent lane, where it wants to drive faster, vehicles outside its field of view (look back distance) are driving faster than the defined maximum speed by this speed difference at the maximum.
ALC_delta_v_min	The minimum difference between the desired speed of the ego vehicle and the actual speed of the lead vehicle that prompts the ego vehicle to change to the adjacent lane, where it wants to drive faster, provided it has already approached the lead vehicle sufficiently.
ALC_gamma	Factor that, when multiplied by the lane change duration (in seconds), approximately results in the time required by the ego vehicle during which the safety distance to the lead vehicle is not shorter than permitted. If the safety distance is likely to be shorter than permitted, the ego vehicle can start to change lanes.
ALC_tau_d_r_faster	Minimum gap time to the trailing vehicle on the faster target lane. There will be no lane change, if the length of the time gap is too short.
ALC_tau_d_f_faster	Minimum gap time to the lead vehicle on the faster target lane. There will be no lane change, if the length of the time gap is too short.
ALC_T_r	At this point in time after the start of the lane change, the ego vehicle estimates whether the trailing vehicle in the adjacent lane would have to brake too hard.
ALC_tau_ego_faster_direct	Time during which the ego vehicle covers the distance that is at least necessary to the trailing vehicle in the adjacent lane, so that it does not have to brake too hard when the ego vehicle changes to the lane of the trailing vehicle. The value is included in the calculation used by Vissim to find out how hard the vehicle would need to brake. The ego vehicle only changes to the adjacent lane, where it wants to drive faster, if the trailing vehicle in the adjacent lane does not have to brake too hard as a result.
ALC_v_limit_max	Maximum speed that the ego vehicle assumes for vehicles outside the field of view (look back distance) when it changes to the adjacent lane, where it wants to drive faster.
ALC_a_ego_d_f_acc	The maximum deceleration the ego vehicle accepts for itself as a result of changing the lane and braking towards the new lead vehicle.
ALC_T_overtake	Maximum time until the predicted start of the next overtaking maneuver. If the predicted time is longer, the ego vehicle wants to switch to the adjacent lane, where it wants to drive slower.
ALC_tau_d_r_slower	Minimum gap time to the trailing vehicle in the target lane, where it wants to drive slower. There will be no lane change, if the length of the time gap is too short.
ALC_tau_d_f_slower	Minimum gap time to the lead vehicle in the target lane, where it wants to drive slower. There will be no lane change, if the length of the time gap is too short.
ALC_T_r_cancel	Analogous to the attribute 'ALC_T_r': During the lane change, the ego vehicle continuously checks whether the trailing vehicle in the adjacent lane is likely to have to brake too hard, and therefore whether the ego vehicle needs to abort the lane change. Typically, a smaller value is used than at the beginning of the lane change, as the trailing vehicle has already had time to adjust to the lane change.
ALC_lambda_LC_cancel	Abortion of the lane change occurs with a quicker lateral movement than the original lane change. 'ALC_lambda_LC_cancel' describes the relative duration of the lane change abortion.
ALC_tau_dot_ramp	At the beginning of the lane change, a reduced gap time to the lead vehicle in the adjacent lane is accepted: In order to prevent the ego vehicle from reacting abruptly, this gap time is continuously increased until it reaches the regular gap time. 'ALC_tau_dot_ramp' describes the speed at which the adjustment progresses.
AutLnChg	Automatic lane change: If the option is selected, the decision model for the lane change of autonomous vehicles becomes effective.