When riding a bicycle on Virginia’s roadways, cyclists generally have the same rights and duties as drivers of motor vehicles. They are required to ride with the flow of traffic and obey all traffic signs, signals, lights, and markings. Although cyclists may have these same rights, in the real world not all drivers appreciate having cyclists on the roads. Bicycles can cause delay or some drivers may think they simply get in the way. Knowing this, most cyclists try to be particularly courteous on the road. Since we share the road, it makes sense to be polite and cooperative while riding – staying to the far right of the roadway, indicating the direction before turning, and generally not impeding the movement of traffic. This attitude is more than just good manners. When a bicycle and a motor vehicle collide, the bicyclist almost always ends up with more serious injuries.
But can being polite cause you trouble? Frequently, a car and a cyclist approach an intersection at the same time. Out of courtesy, the cyclist may indicate to the driver of the car that they can go through the intersection before them or cross in front of them to make a turn. Similarly, on a two-lane roadway, a cyclist may wave a driver behind them to go around them to avoid holding up traffic. Normally, the gesture is accepted and each goes their separate ways. But what if an accident occurs afterwards – another car comes through the intersection and hits the car or the roadway was not clear for the driver to pass the cyclist. Can the cyclist be held liable? Possibly.
Virginia courts adhere to the principal that a person who decides to act – even if gratuitously – may become subject to the duty of acting carefully if he or she chooses to act. A court would look at all the facts to determine whether the wave or other gesture communicated could reasonably have been interpreted to mean that it was safe to proceed, and if the person who saw the wave could reasonably have - and did – rely on the wave.  If your wave could reasonably be considered as a signal to proceed safely and that the way was clear, when it was not, then you could face liability.
All in all, cyclists are better off avoiding the inclination to wave or make other gestures to other drivers. You are under no obligation to do so and could be assuming responsibility for the other person’s safety. While you may mean the wave only to mean that you will let the motorist proceed, the motorist may interpret your wave to mean the way is clear from other vehicles also. The opportunity for misinterpretation is too great; better to refrain from waving under these circumstances.
 See Va. Code Ann. § 46.2-800, at http://leg1.state.va.us/cgi-bin/legp504.exe?000+cod+46.2-800.
 See Va. Code Ann. § 46.2-830 at http://leg1.state.va.us/cgi-bin/legp504.exe?000+cod+46.2-830, and § 46.2-833 at http://leg1.state.va.us/cgi-bin/legp504.exe?000+cod+46.2-833.
 See Ring v. Poelman, 240 Va. 323 (1990); Cofield v. Nuckels, 239 Va. 186 (1990) at http://scholar.google.com/scholar_case?case=5485366678160909927&q=Cofield+v.+Nuckels&hl=en&as_sdt=6,47&as_vis=1; Nolde Bros., Inc. v. Wray, 221 Va. 25 (1980) at http://scholar.google.com/scholar_case?case=6324204545314040720&q=Nolde+Bros.,+Inc.+v.+Wray&hl=en&as_sdt=6,47&as_vis=1.
 For instance, in Nolde Bros. v. Wray (see previous footnote 3), the Court held that the person who waved was clearly not in a position to see the motorist who struck the plaintiff, so that the motorist who pulled out could not have reasonably relied on the wave to mean the way was clear.