Temporary traffic-control sign
Detour to the left ahead
Thai road sign ตค.8: Detour to the left ahead. Meaning: This rectangular orange advance sign warns that the designated temporary detour ahead turns to the left. Catalog status: additional official road-sign reference.
Thai name: ป้ายทางเบี่ยงซ้าย
Independent English reference · Source: Department of Highways · Sign ตค.8
Road response
On the road
Driver action
What should you do?
Reduce speed, watch for work-zone traffic control, and prepare to follow the left detour.
Exam-style scenario
Read the situation
An advance text sign says the left detour is approaching, but the actual turn is still farther ahead.
Best response: Prepare for a left detour farther ahead but do not turn until the decision-point direction sign.
Sign comparison
Don’t confuse it
This sign
Detour to the left ahead
Compare with
Detour to the right ahead
Key difference
This advance text notice says the later detour will be left; the matching notice announces a right detour.
Put sign knowledge into practice.
Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.
