Survey-speak translation needed

[+Black Dog Trackers]

What is the sentence after "Heming Avenue'" saying in this description?

[ArtMan]

The "sentence" reads:

50'' RIGHT STA 567/15 BASE LINE NBL ROUTE 495.

 

Not entirely sure, but I think it has something to do with Beltway traffic being backed up all the way back from the Wilson Bridge through the Mixing Bowl

 

ArtMan

 

(Translation for those not familiar with the DC area: I-495 is the Beltway, and the Bridge and Bowl are two infamous bottlenecks. It's why I take Metro.)

[+Black Dog Trackers]

LOL

 

Well, I'm off to look for this one instead.

 

Hopefully, I'll see powerpole BDT 17.

[Z15]

That reads more precisely as 50 feet right of plan station 567+15 Base Line North Bound Lane Route 495.

 

Construction plans are reference to what they call stationing. All construction is referenced to this working base line or legal centerline. Picture a line on a plan. The starting point know as the Point of Beginning (POB) for this example will be 0+00.00. This means 0 but it could start at any number, e.g. 100+00.00. Every 100 feet along this line (centerline of the road) is called a station 1+00 would 100 ft from the POB, 25+00 would be 2500 feet and 567+15 would be 56,715 feet and then 50 feet right of the line to the mark. Its hard to picture unless you have seen road plans.

 

Unless you have the plans for reference, its may be nothing but most all concrete pavement has this stationing stenciler into the concrete surface along the edge of the pavement. Along in Michigan and other states possibly, there are markers along some road with these information on it.

 

Only an Civil Engineer would understand. I have some ROW Maps and I'll see if I can scan a image that shows stationing.

 

Here is a ROW Map for US-41

 

 

[This message was edited by elcamino on June 29, 2003 at 01:42 PM.]

[survey tech]

The stationing number is a calculated point along the linear road alignment base line, which would be shown on plans, but is not likely to be physically marked, so its of little or no help without the plans. NBL stands for north bound lanes. So its somewhere along the north bound base line, probably in an area off limits to pedestrians anyway. (Never mind, EC beat me to it.)

[+Kewaneh & Shark]

"Details for Benchmark HV7989 in FAIRFAX county, VA"

"Official History

1974 by NGS (MONUMENTED)

DESCRIBED BY NATIONAL GEODETIC SURVEY 1974 SPRINGFIELD. SET FLUSH IN TOP OF NORTH WINGWALL OF WEST ABUTMENT OF NBL ROUTE 495 OVER HEMING AVENUE. 50'' RIGHT STA 567/15 BASE LINE NBL ROUTE 495."

 

This is most definately a confusing sentence, but here's what it means. In highway construction a 'baseline' is used as a reference for construction purposes. That baseline is usually run down the center of the highway and begins at one end of the project and terminates at the other end. Sometimes on wide projects, there is more than one baseline. Thess baselines are then 'stationed', either in feet or meters, depending on which measurement unit the project is using. This stationing begins at the beginning end of the baseline, usually with round number greater than zero, such as 100 or 1000. Stationing nomenclature looks something like this: 1000.00 feet equals 10+00.00 stationing.

 

With the stationed baseline in place, offsets to the right and left of the baseline can be used to define an exact location for a construction item. Right and left of the baseline is defined by the stationing also. As you move up the baseline, with the stationing increasing, right is to the right and left is to the left.

 

What the sentence is saying is '50 feet right of station 567+15 on the baseline for the north bound lanes of Route 495'.

 

This mark is most likely on the shoulder of the highway, and is most likely well used and maintained by the DOT. Be careful. It could be a dangerous location.

 

Keep on Caching!

- Kewaneh

[+Kewaneh & Shark]

Looks like we're all thinking the same thing at the same time. ElCamino is just faster at typing.

 

Keep on Caching!

- Kewaneh

[+Black Dog Trackers]

Thanks guys!

 

The next time I run into that type of reference I will know all about it, including what NBL means.

 

I think I shall not go looking for that station.

 

Today, I did the other one instead, and it was a very hot little walk in the sun.