Setting Out a Curve, step by step
Tangent points first, then pegs at a chosen chord interval.
- Fix the intersection pointWhere the two straights would meet, and the deflection angle.
- Choose the radiusFrom the geometric standard for the class and speed of road.
- Compute tangent lengthT = R tan(Δ/2), measured back along each straight.
- Mark the tangent pointsWhere the curve leaves one straight and rejoins the other.
- Compute the chordsChord length and deflection angle for each peg interval.
- Set out and checkPeg by deflection angle, then verify each peg by coordinates.
Educational reference. Transition curves and superelevation development follow the road authority's geometric standard.
Questions about the Setting Out a Curve poster
- What’s on the Setting Out a Curve poster?
- 6 numbered steps. Tangent points first, then pegs at a chosen chord interval. Fix the intersection point — Where the two straights would meet, and the deflection a…; Choose the radius — From the geometric standard for the class and speed of road.; Compute tangent length — T = R tan(Δ/2), measured back along each straight.; Mark the tangent points — Where the curve leaves one straight and rejoins the other.; Compute the chords — Chord length and deflection angle for each peg interval.; Set out and check — Peg by deflection angle, then verify each peg by coordinates.. Educational reference. Transition curves and superelevation development follow the road authority's geometric standard.
- Who is the Setting Out a Curve poster for?
- Setting Out a Curve belongs to the Civil Engineering section rather than to a school year, because engineering is not something one grade owns. Anyone learning surveying can pin it up — a beginner, a student mid-course, or someone revising years later.
- When should you use the Setting Out a Curve poster?
- Setting out a road, kerb line or track alignment on site. A wall chart earns its place by being glanceable from where the work is happening, so Setting Out a Curve belongs on the wall where that engineering work actually happens, within glancing distance, rather than filed away.
- What other posters go with Setting Out a Curve?
- Areas & Volumes, Bearings and Contours sit alongside Setting Out a Curve in the Civil Engineering section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Areas & VolumesBearingsContours
- Is the Setting Out a Curve poster free to download and print?
- Yes. Setting Out a Curve downloads as a free PDF with no account, no email and no watermark, like everything else in the Civil Engineering section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
- What size does the Setting Out a Curve poster print at?
- Setting Out a Curve is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Setting Out a Curve loses nothing.Printing guide
Related posters
Charts that sit alongside Setting Out a Curve on the same wall.
Browse every Civil Engineering poster, or start from the full catalogue.