Public Works: Transmap for Pavement, Sidewalk, Curbs/Ramps and Traffic Sign Indexing

The Challenge

The Street Division of the Public Works Department annually develops a paving list that schedules the repair and maintenance of the city’s 234 miles of street of street network. A major factor in developing this list is the Pavement Condition Index (PCI) rating, which is a numerical rating based on specific observations of the pavement’s surface conditions. Staff utilizes PCI to prepare targeted maintenance and repair improvements, as well as the annual paving list. Traditionally the Street Division would utilize manual field inspections, with multiple personnel, to collect PCI ratings. This was a very time consuming process and only sections of the city could be inspected at any one time, which meant that a single, complete and current PCI inventory for the entire street network had never been done before. Additionally, since traditional visual inspection methods rely on a subjective evaluation, the assessment can differ slightly from inspector to inspector. Because of these factors, an inventory for sidewalks, curbs and signage had never been completed either.  How can the City collect data on our roads, sidewalks and signage more efficiently so that the data is standard and is entirely current?

The Idea

Street Division staff attended a regional asset management conference in Cincinnati during the spring of 2017.  They learned of a new mapping technology service being offered to municipalities that could drastically reduce the time it takes to evaluate city streets. It utilized Light Detection and Ranging (LIDAR) technology and thermal imaging cameras mounted to a vehicle that would scan not only the PCI of streets, but also capture infrastructure data for sidewalks, curbs, Americans with Disabilities Act compliant ramps and traffic sign reflectivity in a matter of just a few months.  LIDAR is more precise and consistent than field inspection because the data being collected used the same method. 

On November 14, 2017 the Board of Public Works approved a contract with the Transmap Corporation to perform this LIDAR inventory assessment for Bloomington. A vehicle drove around the city and scanned every street, sidewalk, curb, ramp and sign -- detailing the condition of each.  

The Cost

The cost of contracting with the Transmap Company for this service was $124,229.18 and funding was split between the Mayor’s Innovation Fund and the Street Division.

The Benefit

The LIDAR technology provided more consistent data allowing for more efficient street prioritization of repairs and maintenance. This collection of data was much faster than traditional methods and for the first time ever, the Street Division had an accurate and complete PCI street rating, sidewalk, curb, ramp and signage condition picture for the entire city. Staff are now able to spend more time conducting targeted infrastructure analysis and improvement plans rather than simply collecting data visually in a piecemeal fashion. All of the data collected by Transmap is available to the public on the B-Clear data portal. Street Division staff would like to conduct another LIDAR infrastructure field survey in 2021.

Metadata

City Department(s): Public Works

City Department Point(s) of Contact: Joe VanDeventer, Director of Street Operations

Partner(s): Transmap Company

Type of Innovation: Technical/Software

Date Implemented: 2018