Feasibility of nosing:

The differences in speed between the subject vehicle and the vehicles in the target lane are examined to determine whether a nosing is feasible. A nosing is feasible only if the subject vehicle is capable of reaching a speed, by either accelerating or decelerating within its capability (i.e. maximum acceleration or deceleration rates) at the current speed, faster than the lag vehicle and slower than the lead vehicle in the target lane. The requirement of this ``speed match'' can be represented by the following two constraints:

where:

,

acceleration rate and speed of the lead vehicle in the target lane;

normal deceleration rate of the lag vehicle in the target lane;

subject vehicle's maximum acceleration and deceleration rates respectively;

current speed of the subject vehicle; and

T

time period, a parameter to be estimated.

The above conditions are examined in every iteration for the vehicles in mandatory lane change state. If nosing is feasible, the lag vehicle is tagged to yielding state and the subject vehicle is tagged to nosing state. A nosing vehicle applies the maximum acceleration rate for following the leading vehicle in the target lane (subject to a minimum lead gap constraint). A yielding vehicle applies the car-following acceleration rate with the target vehicle as the leader (subject to the normal deceleration constraint).