Miles from delay

The right mapping and surveying can accelerate pre-construction tasks

Accelerated Construction Article June 16, 2004
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No matter how old, how dangerous the road or how routine the project, no road construction gears up until the funding is approved. Some projects may wait on the pending list for years. And when the funding is finally allocated, everyone wants to get started now.

Businesses and individuals served by the route may have been lobbying their lawmakers for years. And when they win the funding battle they want to see earthmoving equipment.

But the reality is that once funding is approved, there are still a host of pre-construction activities—from right-of-way acquisition to environmental compliance to final design—and all depend on the even earlier step of survey and mapping data acquisition. You can practically hear the public and the legislature tapping their toes in impatience while the preliminaries are accomplished.

In an effort to speed the process, the Kentucky Transportation Cabinet (KYTC) has come up with three key steps to efficiency:

  • First, they solicit and award statewide open-end contracts with qualified professional firms to provide photogrammetric and surveying services on demand;
  • Second, they set mapping standards to accommodate not only today’s project, but also unexpected needs. That allows Kentucky to be very responsive to inquiries about potential industrial and commercial sites along a very accessible highway or roadway network; and
  • Third, they are willing to experiment with new technology that offers faster and better solutions for data collection and mapping.

Quickly turn around

Using a quality photogrammetry and survey consultant such as Woolpert LLP for an example, we’ll look at how these three steps have accomplished not only efficient turnaround times on project preliminaries, but also cost-efficient results.

During fiscal year 2002-03, Woolpert completed photogrammetric mapping services for 18 work orders covering some 97 miles of roadway projects, using data-gathering technology ranging from surveyors on the ground with electronic EDMs and GPS equipment to aerial photography and laser-technology LiDAR systems.

1. Open-End Contracts

There’s nothing new about open-end contracts for mapping and surveying. Many states have used them for years. But they remain an important tool for quick turnaround. At present, KYTC keeps four companies on open-end contract for mapping and surveying work. If each job order had to be negotiated separately, it could cost the state six months to a year delay per job.

Open-end contracts also allow the state to bundle aerial photography sessions for multiple projects. Because the optimum flying times usually come in the fall and the spring, a proj-ect can be delayed for months waiting for a good, leaf-off flying time. But if the state deals with a group of prequalified firms, it can schedule the photography for all the projects slated for design and have all the base mapping ready when the design team is ready to begin.

Moreover, the relationship built in an open-end contract serves the state because KYTC knows which firms are best at which kind of work.
With the resources of four firms to choose from, KYTC can pick by capabilities and expertise and, when that’s not a factor, by which firm is closest to minimize travel and per diem costs, and also by which has the personnel and equipment available to get the job done most promptly.

In addition to the time saved in contract negotiations, there are two more important values hidden in the open-end relationship. First, they promote good communication between vendor and agency, so it’s easier to talk frankly about data standards, potential technological solutions and other issues, making sure the state’s taxpayers get the most for their money.

Second, open-end contracts are usually developed with and awarded to prequalified firms. The prequalification process ensures that the transportation agency will be getting the support they need from a consulting firm that has made the investments in staff, training and technology to delivery of a high-quality and cost-effective service.

In states where prequalified, open-end contracts are not used, design firms are allowed to select the mapping and survey firm. This, in turn, often means that the survey and mapping firm is picked by a low bid, which can, in turn, result in poor quality base plans, so problems with coordinates and elevations surface after the construction phase begins. Horror stories of pavement section elevations missing by more than 2 ft are not uncommon.

So the open-end contract saves time, not only at the point of negotiations, but also through efficient data gathering, and, because prequalified firms are used, throughout the design and construction phases, too.

2. Mapping Standards

It would be nice, perhaps, to map every highway corridor in such detail that when a big company asked about locating nearby, you could simply pull up the old mapping data and answer all their questions.

But that would not really be cost-effective, because most roadsides never receive that kind of public scrutiny. And paying for mapping that’s more detailed than the present job requires would be wasteful.

The key is to set the optimal standards for the job on hand, but to perform the mapping so if another project comes up in the same area, the ground control and mapping, involving can be reused as part of the more detailed data capture.

When a project moves from corridor selection to design, it requires much more precise mapping-lower altitude photography, more control and more detail capture. But if the original project was done well, the control is already in place and usable.

It takes only a little extra time to make sure the control is reusable, a negligible cost for the original project, but a real cost-saver for any subsequent work in the same vicinity.

The dividends show clearly in KYTC’s experience trying to lure a major new Hyundai plant. Woolpert had mapped the highway corridor for an earlier project. When Hyundai wanted to know about locating along the new highway, Woolpert was able to turn around the detailed mapping in just two weeks. Hyundai eventually chose another site, but another company is now considering the same site, and the mapping was in hand, ready to answer their questions.

3. New Technology

Finally, to get the best results, states need to be open to new technology. KYTC routinely faces the need to get accurate survey and mapping data in narrow mountain valleys.

LiDAR is a good example. Back in the late 1990s, KYTC needed quick turnaround on a project, but it was December, the sun angle was bad and the terrain was difficult.

It would have been possible to put surveyors on the ground, but not cost effective and not quick. The state turned to its subcontractors for advice and tried the laser-GPS based LiDAR for the first time. It proved effective for the terrain and stood up to the state’s field checks. And since then it’s become less expensive, quicker and more reliable-especially useful because it eases the restrictions on flying seasons and daylight requirements.

Because the consultant recommendations have been good, KYTC has been able to rely on their open-end contract partners to handle the details-rather than micromanaging projects-and is now advancing their technology through the use of subsurface utility engineering data collection techniques, helicopter-based very low-altitude photography and 3-D laser-scan surveying, a ground-based system for collecting detailed digital data on bridges, industrial plant sites and similar features.

Using these three basic tenets of project implementation has helped KYTC be responsive to the needs of its highway designers and, ultimately, the people of the state. This also has paid off in an unexpected way.

The mapping includes a digital orthophoto layer, so when state design engineers and consulting engineers follow KYTC’s new “Thinking Beyond the Pavement” program in soliciting public input, the public can look at preliminary design concepts overlaid on aerial photos and see just what each alternative involves and what effect it would have on property owners and on the environment.

About the author: 
Semones is statewide survey coordinator for the Kentucky Transportation Cabinet, and Slijepcevic is a senior photogrammetry project manager for Woolpert LLP.
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