<P> Weigh Stations (aka "Scales") are usually on the right - hand side of the travelled highway, but median scales are appearing (as of 2005) on divided highways, often combined with "weigh - in - motion" technology . </P> <P> A median scale is placed between the opposing lanes of traffic, necessitating heavy vehicles exiting from the left lane (rather than the right) and re-entering traffic from the left, potentially at a lower speed than the normal "free - flow" traffic would expect in the left (often thought of as "fast") lane . </P> <P> "Weigh - in - motion" technology allows heavy vehicles that do not exceed limits of weight (and size) to pass the scale, thus improving both freight and weigh scale operation efficiency . </P> <P> In Alberta, scales can be on either side of the road, on the median or off - highway . Flashing lights inform drivers as to whether the scale is operational . Occasionally, the lights may be operational in only one direction . </P>

Who has to stop at weigh stations canada
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