Surveyors Bring Safety to 'Boulevard of Death'
In the following article, see how surveyors utilized completely new technology to bring safety to New York's infamous Queens Boulevard.
Since 1990, 185 New Yorkers had lost their lives along Queens Boulevard — most of them pedestrians — and Mayor Bill de Blasio decided it was time to stop this so-called “Boulevard of Death” from killing again.
The mayor announced in summer 2015 that $100 million would be set aside for the project as part of his Vision Zero. “We don’t accept that streets like Queens Boulevard have to be dangerous, that children and grandparents have to be taken from their families year after year,” de Blasio said when announcing the project. “And so… we are taking action on one of the most ambitious and complex overhauls ever undertaken by the city. This street has earned the name ‘Boulevard of Death.’ Today, we begin work on the ‘Boulevard of Life.’”
On the official New York City website, it states the goal for Queens Boulevard to be “bringing safer crossings and more crosswalks for pedestrians, protected bicycle lanes, expanded medians with trees and plantings, and reconfigured intersections that deter speeding and other dangerous behavior.” And, the mayor wanted all this to happen as quickly as possible. So quickly that all the tasks that needed to be done would have to be accomplished in an accelerated time frame that had never been achieved before. Nelson & Pope was part of the team that was chosen to make this vision happen and we knew that failure was not an option. We determined that we had to learn and utilize completely new technology to accomplish the task.
Responding to Urgency
Knowing the urgency of the program, William Oatman, chief of project management for the Program Management Division/Bureau of Site Engineering of the New York City Department of Design and Construction (NYCDDC), turned to one of his top consultants, the joint venture of N&P-GdB (comprised of Nelson & Pope Engineers and Land Surveyors, and Gayron de Bruin Land Surveying & Engineering, PC).
N&P-GdB would have to coordinate numerous personnel, specify tasks for each firm, coordinate proper equipment/software, and coordinate seamless data transfer between the firms to provide the required deliverables — pre-engineering basemapping that would meet all NYCDOT specifications — in the timeframe required. In addition, N&P-GdB would subcontract with Maser Consulting P.A., who would provide mobile LiDAR (light detection and ranging) services as requested by NYCDDC.
That’s how Nelson & Pope, a multi-discipline planning, engineering and surveying firm located in Suffolk County, together with GdB from Nassau County and Maser Consulting PA, from Red Bank N.J., took on phases 1, 2 and 3, and now phase 4 of this massive project.
None of the mayor’s many goals could be achieved until every curb, crosswalk, manhole, valve, traffic control box and all the underground utilities within 50 feet of the right-of-way were mapped and their condition described. On top of that, or rather underneath, the subway was directly under the center of the road.
The office mapping that was required by New York City DOT was to include very specific sets of plans for each portion of the roadway. This was comprised of:
- Survey control plans with ties to all horizontal and vertical control to be used for future construction;
- Base maps showing planimetric features, ROW mapping and detailed adjoining property information to be used for engineering design;
- Highway profiles for each portion of the roadway;
- Topographic plans with cross section elevations every 50 feet; and
- Underground utility plans and sewer profiles.
Using Every Tool Available
It was clear from the outset that every “high-tech” tool, including software, in the arsenal of surveying tools was going to be necessary to complete this task in the timeframe allotted. (See list below) Utilizing traditional surveying methods was out of the question. First, we couldn’t in good conscience put survey crews out on one of the country’s most dangerous streets with only safety vests for protection, nor could we block or stop traffic on such a busy roadway. Secondly, there was the time factor. Conventional data collection with a total station would just take too long.
|Trimble Dini Digital Levels with Invar Rods||Trimble Business Center for the digital level analysis and Carlson Survey for reduction and balancing of run|
|Trimble R-10 Trimble VRS and Leica survey-grade GPS equipment in static, rapid static and RTK with GNSS capabilities||Trimble Business Center for RTK control processing Leica GPS processing software|
|Riegl mobile LiDAR with DMI wheel-mounted unit||Riegl processing software for mobile LiDAR Leica Cyclone and Leica Cloudworx for verifying the mobile LiDAR data|
|FARO terrestrial LiDAR||SCENE software for registering point clouds from terrestrial LiDAR Carlson Point Cloud for extracting data|
|One-second Trimble Robotic total stations with data collection One-second Leica TCA 1800 robotic total stations with data collection||Carlson Survey for traverse adjustment Carlson Survey for conventional field-to-finish robotic total station surveying|
|Dell Precision Tower 5810xCTO base 64 GB (4x16GB) 2133 MHZ DDR4 RDI MM ECC Intel Xeon processor E5-1630 v 3||Drafting performed in AutoCAD Civil 3D and design files delivered in AutoCAD and Carlson Civil deliverable format|
Phase 1 was accomplished working with Maser Consulting PA and their Riegl VQ-450 mobile LiDAR system on approximately 1.4 miles of roadway, excluding service roads. Nelson & Pope was responsible for surveying and setting the high-accuracy horizontal and vertical control and 80 percent of the final mapping. Phase 1 deliverables were provided four weeks early despite the fact that we had to send crews out with conventional methods to gather information on what was missed due to either large trucks, cars or crowds of people obstructing the scans on the day when they originally collected the data.
Phase 2, 1.3 miles of roadway, was accomplished much the same way, but with GdB working with Maser’s mobile LiDAR, Nelson & Pope doing the control and GdB doing the final mapping.
But for phase 3, a full 2.5 miles of roadway, I decided to try something new – terrestrial (stationary) LiDAR. At N&P we wanted to scan the route by terrestrial LiDAR and eliminate the need to field survey any missed gaps in the point cloud when found. We decided that we would use both mobile and terrestrial and perform half of the phase 3 project mapping using the terrestrial LiDAR data and half of the project using mobile LiDAR data.
Although it took us a week to scan the same area using the terrestrial approach, compared to one or two days for mobile LiDAR, our scan coverage from the sides of the road close to the street intersections were more complete. The advantage of using our own terrestrial scanner was better coverage where needed, 360-degree panoramic photos on each scanned location and a longer window of time to find the most optimal time to scan.
Terrestrial, as it turned out, gave us very accurate data and nearly eliminated the need to go back out and fill in any missed spots by traditional field surveying. Plus, identifying everything that was in the roadway was much easier with the digital color photos supplied by the terrestrial LiDAR, even right down to the type of manhole. It didn’t take much time to decide it was safer to be in the office identifying everything than out on Queens Boulevard in a safety vest walking in and around the busy roadway.
And, with the terrestrial, we could invest in our own scanning equipment, due to the reduced cost – $74,000 ($88,000 with the FARO/PointCloud training, SCENE software, and Carlson Point Cloud software) compared to up to $1 million or more for a Riegl mobile system. And, we could also use it in our own timeframe.
Jim Carlson of Carlson Software recommended we try FARO terrestrial LiDAR, which we did via DiCarlo Precision, even though Carlson joked, “Most people pick something like a parking lot for their first project, not miles of one of the busiest and most dangerous roads with a subway underneath.”
We found it was very easy to learn — at least for utilizing it in the field. Setting up four spheres for each 100-foot width of roadway at 100- to 125-foot intervals along the route, it would take 10 to 15 minutes for the equipment to scan 360 degrees with color digital photos. We also had to be aware of when the subway was going by underneath as the vibrations it caused altered the scans slightly.
Because there were multiple firms working on the project, the hardware and software utilized throughout this project spanned practically every high-tech tool available to surveyors.
Being able to understand and utilize all of the different hardware and software was an undertaking in itself. The project involves processing and analyzing digital level data for miles of differential leveling, GPS post-processing and utilizing CORS data with RTK, traverse adjustment software, point cloud calibration/registration, point cloud extraction and much more.
On the Road
One of the biggest challenges in this project was identifying absolutely everything that was in the roadway. This proved to be easier with the terrestrial, as the color photos it provided made identification easier, especially of the manholes.
The following steps were taken to ensure that NYCDDC accuracy standards were met throughout the project:
- Ran vertical control utilizing digital level to run through all scan control points to make it as good as possible closing to Queens Borough Bench Marks.
- Ran horizontal control utilizing static GPS to set azimuth pairs to be utilized for the traverse control to close an open-ended traverse (for construction purposes).
- Utilized RTK GPS for horizontal mobile LiDAR scan control while measuring utilizing robotic total station for the terrestrial LiDAR scan control. Terrestrial LiDAR control had to be tight horizontally or the software would not register the terrestrial scan.
- Scanned all the physical features with the painted targets for mobile LiDAR while setting spheres on the targets that have horizontal/vertical control values with FARO scanner for the terrestrial LiDAR in the field.
- Download the information into the office and register the point clouds utilizing the SCENE software for terrestrial LiDAR.
- Import the information into Carlson Point Cloud and break it into sliceable bits of information (so that the computer can deal with it) resulting in manageable point cloud data from the billions of points.
- Start mapping.
We called this “slice and dice,” and it enabled us to increase the accuracy value throughout the individual scans.
As using terrestrial LiDAR was a completely new methodology for this type of project, Nelson and Pope ended up writing up a procedure and suggested standards and guidelines for the NYCDDC for both mobile LiDAR and terrestrial LiDAR for surveyors to successfully utilize this equipment on future projects throughout NYC’s five boroughs. Nelson and Pope, Gayron deBruin Land Surveying & Engineering, and Maser Consulting PA also won the 2016 ASCE Long Island Branch Project of the Year/Transportation award for our work.
Using terrestrial LiDAR provided extremely high-quality results in a timely fashion, and was a cost-effective alternate to mobile LiDAR and conventional surveying. The city now has the data it needs to start making the roadway safe. Phase 1 of this project is already under construction and we are using the terrestrial for phase 4. With the learning curve out of the way, we are pleased at how quickly and accurately mapping can safely be produced at a competitive cost.