Recently, I was involved with a project where we needed to locate the rights- of– way of a road that involved a spiral curve. We had record information on the centerline of this road as well as the distances from the centerline to the right-of-way.
I used the TPC spiral command in the COGO section of my centerline traverse to calculate, and draw, the spiral at the centerline. I then used the right-of-way offset command, and TPC calculated the spirals at the right-of-way lines. When I checked the information of these offsets I quickly realized that TPC had actually calculated spirals 50 feet each side of the centerline.
This allowed me to make a DWG file, and send it to my CAD technician to incorporate proper rights-of-way into his drawing.
By using the spiral, and offset commands, I not only have a proper drawing for my CAD tech, but I also have all the proper calculations for every spiral associated with this right-of-way (centerline, and offsets).
Using TPC, I was able to lay out the centerline, offset to the rights-of-way, and get this information to my CAD tech in less than five minutes.
Not only did this save me a great deal of time, but I have all the information I need to defend my calculations.
James A. Coan, Sr., PLS