- Use curve warning signs to communicate downstream changes in horizontal alignment to motorists. Signs need to include a directional arrow that indicates if a curve bends to the left or right. Advisory speed signs can also be used.
- Table 6.5 contains placement guidelines for curve warning signs based on the posted or 85th percentile speed. There are no guidelines for cells that read n/a — placement will depend on site conditions and the presence of other signage. To determine how far upstream of a curve advance warning signs should be placed, first select the posted or 85th percentile speed. Next, determine the curve advisory speed. Then look for the appropriate cell. For example, if the posted or 85th percentile speed is 45 mph and the curve advisory speed is 10 mph, the curve warning sign should be placed 125 ft upstream of the curve.
| Table 6.5 Distance Guidelines for Advance Placement of Curve Warning Signs | |||||||
| Posted or 85th Percentile Speed (mph) | Advance Placement Distance (ft) Based on Curve Advisory Speed (mph) | ||||||
| 10 | 20 | 30 | 40 | 50 | 60 | 70 | |
| 20 | n/a | — | — | — | — | — | — |
| 25 | n/a | n/a | — | — | — | — | — |
| 30 | n/a | n/a | — | — | — | — | — |
| 35 | n/a | n/a | n/a | — | — | — | — |
| 40 | n/a | n/a | n/a | — | — | — | — |
| 45 | 125 | n/a | n/a | n/a | — | — | — |
| 50 | 200 | 150 | 100 | n/a | — | — | — |
| 55 | 275 | 225 | 175 | 100 | n/a | — | — |
| 60 | 350 | 300 | 250 | 175 | n/a | — | — |
| 65 | 425 | 400 | 350 | 275 | 175 | n/a | — |
| 70 | 525 | 500 | 425 | 350 | 250 | 150 | — |
| 75 | 625 | 600 | 600 | 450 | 350 | 250 | 100 |
| Table 6.6 Proper Chevron Spacing | |
|---|---|
| Advisory Speed Limit (mph) | Chevron Spacing (ft) |
| 15 | 40 |
| 20 | 80 |
| 25 | 80 |
| 30 | 80 |
| 35 | 120 |
| 40 | 120 |
| 45 | 160 |
| 50 | 160 |
| 55 | 160 |
| 60 | 200 |
| 65 | 200 |
CONTACT:
Chris VanDyke
Research Scientist | Program Manager
chrisvandyke@uky.edu
