Using the kinematic equations:
(final velocity)^2 = (initial velocity)^2 - 2 * acceleration * distance
Assuming the acceleration/deceleration on the car is constant from a constant force on the brakes. Converting from mph to m/s using 0.447 (so 34 mph is 15.2 m/s)
(0)^2 = (15.2)^2 - 2 * acceleration * 29
acceleration = 4.0 m/s^2
Had the car been going 105.4 mph (47.1 m/s)
(0)^2 = (47.1)^2 - 2 * 4 * distance
distance = 277 meters