traffic sign warns that the high road slope and curvature.

road highway infrastructure lane freeway sign signage mountain advertising driving sky asphalt transport tree hill traffic warns high slope curvature warn truck driver drive carefully steep percent8 downhill gradient background beware black car caution crossroad dam danger dangerous descent discharge forest highway hill landscape mountain nature outdoor park people ramp road roadsign round roundabout safety sign signage sky slippery slope slopes steep street symbol thailand traffic transport transportation travel tree trucking vector warn wild yellow