Chasing Cracks…

Not the same crack that is in the news, but it is pretty addicting…

We’ve built a bunch of new tools centered on pavement crack assessment and we’re excited about how it will increase the transparency related to pavement assessments.  In the past, pavement assessments have been more about delivering segments with PCI values attached to them and less about the actual measurements that were used during the creation of this data.

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Our clients are always quick to say “We went out and checked a few segments and our assessments were different than what was reported”.  This lead to an educational discussion about how the ratings were created and how we applied the ASTM methodology to arrive at these results.  Most of the time we all agreed that there was always some subjectivity in the ratings, but that the standard rating methodology had been applied the same way throughout the network.

Our goal has always been to increase the transparency related to pavement inspections and this new approach has helped us to take a step in that direction.  The process is GIS-centric, as it is with all of our processes and involved a ton of tool development that will continue to evolve over time.  So, here’s what we’re doing…

First, we are collecting crack images using a downward-facing 4k linescan camera system with laser illumination.  This ensures that all of the pavement images are uniform and are not subject to low-lighting or shadows from natural and man-made features.  These images are 1mm resolution, allowing us to see the detailed cracking – especially at the lowest severity levels.

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The following graphic illustrates the output from the crack mapping software we are using.  Cracks are identified in the imagery automatically from the software and are exported as geospatial points, lines and polygons.

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The software does a great job of identifying longitudinal, transverse, and alligator cracking.  Once we have the initial crack map, our team of compilers goes in and edits the crack maps as needed.  Typically, we are editing out false-positives and adding in other distresses as dictated by the scope of work.  This editing is done within our EarthView software and is completely geospatial in nature.  In other words, we can export these cracks, so they can be viewed in a GIS.  This is pretty exciting because all of these cracks can be mapped and themed in a GIS based on their severity levels.

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This process gives the end user of the data a simple QA/QC process that can be used to understand the specific issues related to each segment.  Furthermore, this data is then combined with other GIS data sets (Functional Classification, Traffic Counts, etc.) so that a more holistic approach can be taken towards the determination of which segments need in terms of repair methods.  This data can also be exported to Google Earth for easy viewing and display in a non-GIS software.

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We hope that this provides the end user with more tools in their GIS arsenal to better plan, bid, and execute their Capital Improvement Planning for the year.  In other words, our clients will be able to do more with their limited funding than ever before!

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Sign Retroreflectivity Compliance – A Geospatial Approach

We just completed a sign retroreflectivity shortlist presentation for the a client and discussed the options available for gaining compliance based on FHWA regulations as described in the MUTCD.  The client was sold on the “Blanket Replacement” method by a vendor who specializes in sign replacement.

MUTCD Retroreflectivity Guidelines

I was thinking “what a great selling strategy”, but then I thought twice about it.  This vendor had the ability to write their own ticket for selling their sign materials!  A great strategy for the vendor, but not a good option for the client.

We approached the presentation using a different approach – it combined the concept of risk with the general principles of Asset Management.  First, we would inventory their existing sign network to determine what they had and where it was.  Then, we would prioritize which areas were the most likely to fail based on the average age of the signs as well as the risk associated with the actual failure (e.g. pedestrian injury or vehicle damage due to an accident).

 

Risk Assessment for Signs

 

Sample Replacement Cost Calculation

This approach takes into consideration the entire segment of a road instead of considering an individual asset.  The client believes that it is more cost effective to replace the worst signs along a segment using a single mobilization of field crews, rather than jumping around and fixing signs based solely on their condition.  Therefore, we are combining the geospatial location, condition, age, value and MUTCD to develop a risk score for each individual sign.

Project Life Cycle

This analysis is used to create the biggest bang for the buck for our client by reducing risk related to accidents caused by failing signs.  Since all agencies have to be compliant with Regulatory, Guide and Warning signs by 2015, this approach will support a phased approach while taking care of the highest risk signs and working through the lower risk signs until all non-compliant signs have been replaced or are scheduled for replacement.

Compliance Dates for Sign Retroreflectivity

 

Valuation of Sign Asset

In conclusion, the use of Risk to support the prioritization of asset maintenance serves an appropriate role in saving clients time and money.  By replacing the highest risk assets first, an agency can reduce their exposure to lawsuits related to failing infrastructure.

Executive Dashboard