The Pennsylvania Motor Vehicle Code requires that
[n]o person shall drive a vehicle at a speed greater than is reasonable and prudent under the conditions and having regard to the actual and potential hazards then existing, nor at a speed greater than will permit the driver to bring his vehicle to a stop within the assured clear distance ahead.
75 Pa.C.S.A. s. 3361 (West 2006). While the statute is titled “Driving vehicle at safe speed,” it is also referred to as the “assured clear distance ahead” rule. The well-established assured clear distance ahead rule requires the operator to keep his automobile under such control so that he can always stop within the distance the he can clearly see. Levey v. DeNardo, 725 A.2d 733 (Pa. 1999). It means only what it says, i.e., clear distance that is assured or can be reasonably depended on, not guaranteed. Turner v. Smith, 346 A.2d 806 (Pa. Super. 1975). The Supreme Court, while generally agreeing with Superior Court decisions announcing that the assured clear distance ahead rule generally applies to static or essentially static objects,1 does not believe the rule to be that inflexible. Lockhart v. List, 665 A.2d 1176, 1182 (Pa. 1995). The Court has held that the distinction between a moving or static obstacle is rendered meaningless where the evidence, at least arguably, suggest either that the driver would not have seen the obstacle in time to avoid a collision and/or would not have reasonably foreseen the occurrence of the obstacle, even if prudent.” Id. at 1182-83.
While the assured clear distance rule generally applies to static or essentially static objects, the sudden emergency doctrine generally, but not exclusively, has been applied to “moving instrumentalities unexpectedly thrust into the driver’s path.” Lockhart v. List, 665 A.2d 1176, 1182 (Pa. 1995). The “sudden emergency doctrine” is available as a defense to a motorist who suddenly and unexpectedly finds himself confronted with a perilous situation that permits little or no opportunity to apprehend the situation and act according. Id. The purpose behind this doctrine is to lessen the standard of care for an operator confronted with such a sudden and unforeseeable circumstance because of the shortness of time in which to react. Id. However, the driver seeking to avail himself of the protection of the sudden emergency doctrine cannot be himself driving carelessly or recklessly. Id.
What is a sudden emergency? A sudden emergency which will render the assured clear distance ahead rule inapplicable may be a dust cloud, a moving object, a sudden blocking of the road, the sudden swerving of other vehicles or blinding lights. Unanagst v. Whitehouse, 344 A.2d 695 (Pa. Super. 1975). A sudden fog may also qualify as a sudden emergency where the driver’s actions, including turning down the radio, dimming high beams of headlights, and letting up on the gas pedal, supported the inference that she reacted upon encountering dense fog. Dickens v. Barnhart, 711 A.2d 513 (Pa. Super. 1998) app. den. 729 A.2d 1129 (Pa. 1998). In addition, it has been held that a jury instruction on the sudden emergency doctrine was proper where a motorist struck the car in front of him when another vehicle abruptly turned into the path of the first car and caused a collision. Levey v. DeNardo, 725 A.2d 733 (Pa. 1999). In this case, the defendant, traveling behind the plaintiff, applied his brakes but his car began to skid on the wet surface of the roadway. Id. The court found that a jury instruction on the sudden emergency doctrine was appropriate, as there were no facts to suggest that collision between the first and second drivers was caused by the second driver’s own negligence. Id. at 737.
The sudden emergency doctrine should be pleaded as an affirmative defense in New Matter, and the issue is presented to the jury in the form of a jury instruction. See Pa. S.S.C.J.I. 3.18. If the evidence does not conclusively establish that an emergency situation existed, wholly independent and not created by plaintiff’s own act of negligence or recklessness, the issue must be submitted to the jury. Stacy v. Thrower Trucking, Inc., 384 A.2d 1274 (Pa. Super 1978). An instruction on the sudden emergency doctrine may also be given in a negligence action concurrently with an instruction on the assured clear distance ahead rule if the facts do not conclusively establish the existence of a sudden emergency. Cunningham v. Byers, 732 A.2d 655 (Pa. Super. 1999).
What is clear is that it is appropriate to instruct the jury on both the assured clear distance ahead rule and the sudden emergency doctrine, regardless of whether an obstacle is stationary or moving, if there is any evidence to suggest that an emergency situation existed.