City of Memphis
Street Signs Inventory
In a massive mobile data collection effort spanning two years, CAESER mapped every street sign in the City of Memphis—more than 150,000 in total.
Included with each sign, where applicable, was the Federal Highway Administration’s Manual of Uniform Traffic Control Devices (MUTCD), code, sign customizations (shape, color, lettering), sign post type, and date of installation. Teams of students were sent out each day to drive the streets of Memphis, collecting this information using custom scripts in GIS developed by CAESER.
CAESER designed and developed a mobile data collection workflow and strategy, mobile application, and project database that enabled field technicians to quickly, efficiently, and accurately map all street signs within the public right of way throughout the City of Memphis. CAESER developed a custom data entry application that enabled technicians to locate, code, and attribute street signs without the need to memorize hundreds of sign codes derived from the MUTCD. Rather than having to memorize the sign series and code, users simply had to pick the street sign from a series of buttons, which would then automatically place the appropriate sign code into the database.
Though the MUTCD sign code was the primary attribute that was being identified over the course of this project, technicians were also responsible for collecting nearly two dozen additional attributes that would enable engineers and field crews to accurately identify or replace any street sign mapped as a result of this project. The data entry forms utilized by field technicians ensured a high level of data accuracy prior to entering new data to the database. Intricate relationships among the various attributes were identified prior to the start of the project so that the amount of free text entry was minimized and so that users were only exposed to attributes that were relevant to a particular set of attributes at runtime.
The City of Memphis, Traffic Engineering department made the decision to convert their traffic sign record system from a paper based system to a GIS based system in 2010. The primary reason for this conversion was to be in compliance with new federal guidelines related to Traffic Sign retroreflectivity specified in the Manual on Uniform Traffic Control Devices (MUTCD). The 2009 version of the MUTCD required all agencies to establish a traffic sign management system in an effort to ensure that all signs meet minimum retroreflectivity standards. The first part of the traffic sign records conversion process required a GIS inventory of all traffic signs in the City. The University of Memphis was selected to perform the initial inventory work and to establish a preliminary GIS system to allow City staff to track progress. Since completing the sign record conversion City staff has been able to fully implement a GIS based Traffic Signs Management system that is utilized to create work orders for field staff, track installation dates, and run reports on the number of signs installed or maintained throughout the City. This system has greatly improved the staff productivity and has allowed city staff to spatially view the locations of all signs rather than looking at rough approximate locations on paper records. Staff is now able to investigate many sign requests from the office instead of being required to go out in the field to verify sign locations.
– Randall Tatum, Administrator, City Traffic Engineer