I refer to the letter from Bob Young headlined 'Extra arrows can give drivers earlier warning' (Sunday Morning Post, May 6).
To help drivers get into the correct lane on the approach to a signal junction, we normally provide at least two sets of lane-arrow markings which are at about 15 to 25 metres and 44 to 75 metres from the stop line respectively.
The actual location of the arrow marking depends largely on the approach and the layout of the site. A third set of arrow markings will be added at about 90 to 150 metres from the stop line for difficult conditions such as when the approach speed is high, or the lane allocation is not obvious.
However, it may not always be feasible to place the third set of markings, because of the short length of the approach, especially in urban areas with closely-spaced signalised junctions. In such cases, we would consider putting up additional lane-arrow directional signs on the roadside as a supplement to the lane arrows. Such an arrangement gives a clear indication to drivers so they can choose the correct lane.
TONY YAU
for Commissioner for Transport