Traffic signs AND SIGNALS on approach roads
Figure 1: Approach signs on the run up to a tunnel in Austria
Approach signs and signals are located several hundred metres before the tunnel portal (Fig. 1). They provide information on traffic regulations (speed limits, over-taking prohibited for heavy vehicles, vehicle height restriction etc.).
Approach signs that provide a warning to drivers of the authorised vehicle height may be included into a height restriction device (Fig. 2).
Figure 2: Height restriction signs and barriers on the approach road to a tunnel in Austria