Curve advisory speeds, supported by a study.
We inventory each horizontal curve and its warning signs, determine the advisory speed, and list the sign changes needed to match.
Why agencies order it
The MUTCD says an Advisory Speed plaque shall not be installed until the advisory speed has been determined by an engineering study, and relates curve warning devices to the difference between the advisory speed and the applicable approach speed (MUTCD 11th edition (2023), Sections 2C.05–2C.06 and 2C.59). In Ohio, ODOT’s Traffic Engineering Manual (Section 1213-2) names the ball-bank indicator as the most common method for setting the advisory speed.
What we do
- Inventory every curve and its warning signs and plaques, with GPS location and milepoint.
- Determine the advisory speed by ball-bank, or by the method your agency specifies.
- Compare the signs in place with what the speed difference calls for, and list sign upgrades, post replacements and speed plate changes.
What you receive
- A curve and sign inventory with advisory speeds and imagery.
- Prioritized sign work items.
- Summary reports for a curve-sign upgrade program and its budget.
Using CurveMaster? We continue to support your team and software. For new projects and workflows, this service is available through MapsterStudio. See sight lines measured around a curve on SR 163 ↗
Recent work
- Ohio counties, 2023: 312 miles of ball-bank curve study. Read the project ↗
- Holmes County, Ohio, 2022: 250 miles. Read the project ↗
Want to know how the data behind this study is checked? How we check our work ↗