There are some areas in my area where the monuments were set from center line using a 90 prism or clapped 90. The distances are very tight as they were carefully chained. Soon after the center planting was done and only the r-o-w mons remained. I've retraced many of these.
As some have said the process of recovering the r-o-w established this way is simple. Recreate the tangents and fillet at the proper degree of curve. The monuments fall on the r-o-w but usually miss the station. This method will preserve the location through the curve nuch better than a non-tangent curve. It honors the way the monuments were set.
If you apply this method and it disrupts long-standing occupation you have more work to do. I would encourage you to work through evidence based methods rather than trying things until it appears to fit. Accidentally getting an apparently correct answer without evidence to support it will eventually end poorly...
Highway right of way monuments in Oklahoma are generally only very crudely positioned. Paden has written of how, in the past, they were set by fencing contractors working from half-hearted survey crew guidance. If they fall within single digit feet of the theoretical you are doing well. If nothing else is available hold the mons for tangents, develop a centerline between them, hold the tangency, hold the radii, hold the right of way width. The land is cheap enough that nobody is going to get real exited about a few feet of prairie.?ÿ ?ÿ
We have areas like that as well. Depending on the method of creation the width may yield to the monuments. A lot of guys flip out when you do that...
Or, shoot r/w markers, and use Hwy dpmt radius, holding the r/w markers, even though this makes broken back curves, and odd road widths?
I've always been told R/W markers, formerly known as "mower's markers", weren't set with any high degree of accuracy. The only ones I've ever shot were along Florida's Tpk. in Palm Beach County for an FDOT R/W survey. They had SRD scribed in the side facing the Tpk. along with an "X" scribed in the top.
It is certainly true that many ROW monuments where set by very imprecise methods, but since when has inpresision been a reason to reject "first" monuments??ÿ
Do we shoot centerline, and make all curves tangent?
Is it a requirement that all highway curves should be tangent? Maybe a highway engineer's safety requirement? What's the purpose of the survey? Topo or design? No way I would shoot the centerline of Florida's Tpk. back in 1994. I suppose that would be doable nowadays with a scanner? On that same survey the boss had me locate the edge of pavement. That was not clearly defined because of overpour. I think I wound up shooting the white stripe along the shoulder. Anyway, great question!
IMO, the assumption is that curves are tangent unless they clearly and positively aren't. Remembering that?ÿ highway curves often have spirals in and out.?ÿ?ÿ
The design centerlines of course have to be tangent. It is no fun driving around non tangent curves. But there is no particular reason the right of way curves have to be tangent.?ÿ
High speed highways often are designed with spiral curves, but spiral ROWs are less common.?ÿ
spiral ROWs are an abomination.?ÿ
Hopefully the complaints and discussions to the DOT removed them from future design.
However, the guy that was on board with putting a stop to it retired.?ÿ
It's remarkable how little the mid-point of a curve will differ between a typical spiral-curve-spiral and a simple curve.?ÿ
I'm putting together a property line against an interstate highway, the right of way was designed in the 1950's, simple curves, nearest minute bearings, curves all designed using degree of curve, jogs at even stations, PCs, PTs or property/section lines, frankly a pleasure to work with.
Then nearby is a state highway designed in the early 2000's: ROW spiral-curve-spiral, jogs 15-30' beyond the TS or before the ST, very messy.
From a practical viewpoint I completely agree, but I do enjoy the variety and challenge when I do come across them.?ÿ
But there is no particular reason the right of way curves have to be tangent.?ÿ
Unless it's to keep from contempt,
by those who come behind you! 😉
?ÿ
@nate-the-surveyor Yeah, seems maybe the better way to do it is to shoot the EP and split it.?ÿ Think anyone will pay for that??ÿ ???
Many years ago I was shooting the EP of an entrance ramp to Florida's Tpk. There was a lot of overpoured pavement, and I wasn't sure if I should shoot along the overpour or along the part that the cars actually drive on. I was thinking that if they were going to demolish the ramp, they would need to know the amount of pavement to replace it with. I think I shot both the EP and the white stripe that ran outside the driving surface. What are your thoughts on that?
