Divided Highways

[+msrubble]

Measurement to the mark is from the center of some object (pole, post, road, nearest rail) to the center of the mark. In the case of a divided highway, with a median strip, is the measurement taken from the center of the nearest lane (or set of lanes)? Or is the measurement from the centerline of the whole highway?

[Difficult Run]

When the original description was written, the measurement was made to the existing road at the time.

The second lane is generally added without disturbing the first road.

So, in order to find the mark, you have to determine which lane is the original road.

 

Later descriptions will reference the center of the eastbound, (or west / north / southbound lanes).

The newer lane will generally be level and straight in comparison to the old lane.

 

Care should be exercised when making that measurement, as oncoming traffic can pose a hazard.

 

Good luck in finding the mark.

~ Mitch ~

[ArtMan]

Mitch is correct. Normally, these descriptions date back to a time before the road was a divided highway. Sometimes placement of utility poles can be a clue. I've also seen descriptions that will refer to something like the "centerline of the eastbound lanes"

 

-ArtMan-

[+msrubble]

Here is the situation. I'm sure it is similar to the challenge others sometimes face. A two-lane highway, over the last several years, has been widened in some sections to become a four-lane divided highway. The most recent descriptions are from 1990 at best.

 

If I can find the marks, I would like to make sure the descriptions are up to date. So do I just accept the old distance from the centerline as correct?

 

Or if it is safe to do so, do I take a measurement from the existing highway? And if I should measure from the highway, my question is as in the original post. If someone were describing this mark today, would it be from the centerline of the nearest lanes, similar to the nearest rail of a railroad track? Or would it be from the centerline of both sets of lanes?

[2oldfarts (the rockhounders)]

Here is the situation. I'm sure it is similar to the challenge others sometimes face. A two-lane highway, over the last several years, has been widened in some sections to become a four-lane divided highway. The most recent descriptions are from 1990 at best.

 

If I can find the marks, I would like to make sure the descriptions are up to date. So do I just accept the old distance from the centerline as correct?

 

Or if it is safe to do so, do I take a measurement from the existing highway? And if I should measure from the highway, my question is as in the original post. If someone were describing this mark today, would it be from the centerline of the nearest lanes, similar to the nearest rail of a railroad track? Or would it be from the centerline of both sets of lanes?

 

A simple measurement from the ROW fence line along with a measurement from the closest Edge of the pavement would suffice for most benchmarks. If there are other distinct features that are permanent (or long term) you can provide a measurement from them as well. Don't forget to give the coordinates from your GPSr, since they will get the next person very close to where they need to be looking to find the benchmark.

 

John

[+Trucker Lee]

Care should be exercised when making that measurement, as oncoming traffic can pose a hazard.

For safety's sake, try it this way..... Using a retractable tape measure, pull out about 12-15 feet as you pace backward from the edge of the surface. When traffic clears, walk forward until the end of your tape hits the centerline. Quickly glance at the tape reading at the surface edge, retract the tape, and step away from the highway. Now you just measure from the edge of the road instead of the center. You may wish to chalk mark the point you will measure to before starting. If you need to drive a nail (and remove it when done) to hold a long tape measure, you are now only concerned with traffic going one way, and your nail is not a large traffic hazard (but still put a cone over or next to it).

 

Here is the situation. I'm sure it is similar to the challenge others sometimes face. A two-lane highway, over the last several years, has been widened in some sections to become a four-lane divided highway. The most recent descriptions are from 1990 at best.

 

If I can find the marks, I would like to make sure the descriptions are up to date. So do I just accept the old distance from the centerline as correct?

 

Or if it is safe to do so, do I take a measurement from the existing highway? And if I should measure from the highway, my question is as in the original post. If someone were describing this mark today, would it be from the centerline of the nearest lanes, similar to the nearest rail of a railroad track? Or would it be from the centerline of both sets of lanes?

 

May have to check with the local highway engineer's office to see how the road was widened. If a lane added to both sides, the old centerline is correct. It could have been faster, safer, and less expensive to just add one or two lanes to one side, in which case the lane divider for one side would be the old centerline (roughly a 12 foot difference) or the middle of a lane. On divided highways, as noted above, one side is often the original, the engineer's office would know. As for safe measuring, see above.

 

Benchmarks are often placed on the edge of the right of way in my area. Another clue would be to guesstimate the age of the volunteer trees and the depth of the yards along the road. If the houses are near the same age, and the south side of the road is most commonly about 40 feet closer, that is probably the newer side if additional right of way was needed.

 

Edited for clarity.

Edited April 28, 2007 by Trucker Lee

[+Renegade Knight]

...May have to check with the local highway engineer's office to see how the road was widened. ...

 

Centerline, Construction Centerline, Survey Control Line etc. etc.

The only way to know for sure is to follow the above advice. Reading the plans tells you exactly whats what...at least from the last time the road was improved.

[2oldfarts (the rockhounders)]

Before heading out to measure from the center of the highway, try measuring a set distance where you can walk unimpeded. Try for 30 feet to start with. Mark the distance on the ground for a start and finish point. Now "Pace" that distance and count the paces. Try this at least 10 times. When you get a feel for how many paces it takes to cover the starting distance, try pacing twice that number of paces and then measure it with a tape. How well did you do? How far off was your pacing for the longer distance?

 

With practice you will get a feel for how many paces to make from a given point to reach the desired distance.

 

Once you're comfortable pacing a distance, you simply walk to the center of the road (when there's no traffic ), turn and pace off the distance in the required direction. This is then the time to get out the probe if the mark has been covered over by dirt and debris.

 

The only amount of time you are in the center of the road is the amount of time it takes to walk to the center and turn around and walk back to the edge of the road.

 

Once you have actually found the mark then you can make measurements from points that are not in the middle of the road (poles, fences, trees, etc) and include them in your report along with updated coordinates if the ones on the datasheet are scaled. If the datasheet coordinates are adjusted there will be no need to provide updated coordinates, because the given coordinates are so accurate already.

 

John

[mloser]

I read the IP to ask where the center of the road is in a divided highway.

 

If that means a highway with a small concrete median, or the New York barriers between opposing directions of traffic, chances are that the center is that median. In the case of a truly divided highway with a grass area between directions, then it most likely means the center of the two nearest lanes. Typically the datasheet will say where the measurement is from in this sort of situation--"47 feet west of the center line of the westbound lanes". The idea was to get a good measuring point, not to find the center of a road right of way. Centerlines are used because often the edge of the road is rough or even slightly buried, and it may be hard to determine where it is. And when roads are widened, especially in the case of country roads, they are often widened symmetrically.

 

Something to note, and I use it often on busy roads: I read somewhere (most likely Wikipedia that standard lane widths for interstates are 12 feet, so I often use that figure as a starting point, then run a tape TO the edge of the road (the traffice lane, not the shoulder, if possible) when traffic clears, add the two figures, and then finish measuring. This is usually good enough. For non-interstates I guesstimate 11 feet, country roads, 10 or even 9 feet, although with the smaller roads it is usually possible to tape to the center and get a decent read--again, I pin the tape to the ground about where I think I should end up, walk to the center of the road letting the tape out, touch it to the center and walk back. Then I check my measurement and correct as needed.