<P> Note that the 2009 Manual of Uniform Traffic Control Devices prohibits any display that gives warning of an upcoming signal change, unless that display is placed well upstream of the signal (See "Warnings of traffic light ahead" below), so traffic at the stop line cannot see it . </P> <P> At some intersections in Quebec, Canada, the yellow and red lights will appear together to indicate that the light is about to change to red . This mitigates the fact that at most Quebec intersections, there is no delay between the time that the lights in one direction turn red and the lights in the perpendicular direction turn green . However, this is considered redundant in other places, as the yellow light itself indicates that the light is about to change to red . </P> <P> In most European countries (including Austria, Belarus, Bosnia and Herzegovina, Bulgaria, Croatia, the Czech Republic, Denmark, Estonia, Finland, Germany, Hungary, Iceland, Latvia, Lithuania, Macedonia, Malta, Moldova, Montenegro, Norway, Poland, Russia, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, and the United Kingdom), as well as in Argentina, Botswana, Colombia, Hong Kong, India, some places in Indonesia, Israel, Liberia, Macau, Pakistan, Paraguay, and South Africa, the red and yellow lights are displayed together for one, two, or three seconds at the end of the red cycle to indicate that the light is about to change to green . This phase aids the drivers of vehicles to turn on the engines again (there are requests / advices to turn off engine in front of red traffic lights in some countries, e.g. Switzerland), or drivers with manual gearboxes, giving them time to change into first gear during the short phase, as well as drivers of vehicles that may have been yellow - trapped whilst turning right a chance to clear the intersection in more safety . It also informs drivers who may be approaching the intersection at speed that a green light is imminent, so they may proceed through the junction without having to stop (or, with enough of a lead distance, even having to slow), reducing the potential annoyance (and safety risk) of braking sharply to a halt only to have the green light appear immediately after . </P> <P> In some areas, a "prepare to stop" sign with two alternately flashing yellow lights is installed in locations where a high - speed road (design speed usually at least 55 mph / 90 km / h) leads up to a traffic light, where the traffic light is obscured from a distance (or both conditions), or before the first traffic signal after a long stretch of road with no signals . This is installed so that drivers can view it from a distance . This light begins blinking with enough time for the driver to see it and slow down before the intersection light turns yellow, then red . The flashing yellow light can go out immediately when the light turns green, or it may continue for several seconds after the intersection light has turned green, as it usually takes a line of cars some time to accelerate to cruising speed from a red light . These are relatively common in areas such as the United States, Canada, Western Australia, New South Wales and New Zealand . Japan uses a variant signal with two lamps, a green one and a flashing yellow one, for the same purpose . </P>

Who may proceed when a red arrow signal is displayed