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Winter 2001/2002
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Boulder County, Colorado, Sign Maintenance Receives Big Dividends from ArcPad

  screen image of Boulder County street intersections; click to see enlargement
A screen image of Boulder County street intersections.

In 1995, the Boulder County Road Maintenance Department in Colorado made the decision to establish their own centerline, sign, culvert, bridge, and other transportation layers using Trimble Pro XL GPS equipment. This produced a spatially accurate map with attributes for each feature including a unique identifier attached to all items in the form of a bar code. The available GIS layers from the other Boulder County departments at that time were digitized and not considered spatially accurate enough in the mountain areas for sign placement and culvert location. Once the mapping and inventory process was completed it was necessary to maintain the integrity of the data by updating information as it changed in the field. ArcView and ArcInfo by Esri were chosen to manage the different layers. It also became necessary to make the data available for use by maintenance crews. ArcExplorer was chosen for this because of its ease of use and its being a free downloadable program from Esri--the price was unbeatable.

The same map above displayed with ArcPad on a Casio
The same map displayed with ArcPad on a Casio.

From a division standpoint, road signs are second only to road condition as the most prevalent source of transportation-related litigation. Maintaining sign configuration on a section of road as originally intended by a traffic engineer becomes more difficult over time as signs are replaced, damaged, or stolen. This can make government entities vulnerable to lawsuits and put the motoring public at risk from inadequate or improper signage.

Previously, paper maps and videotapes were used to establish sign placement and content information. When performing inspections of a road section, updates or replacement of missing signs required a minimum of two trips to an office for comparing memory to the maps and videotapes.

Following the development of a GPS-produced map and sign database, employees could view sign information using ArcExplorer but this still required multiple trips into the office from the field. Keeping the sign database current and accurate was also a problem as there was a time delay in acquiring the daily employee time sheet data and then entering that information into the sign database. The time sheets are a log of the Sign Shop employees' daily activities and contain information such as a sign bar code number and what work was performed. A unique bar code number is assigned to each sign. If an employee entered the wrong bar code number, the data would be associated with the wrong sign in the database. This damaged the accuracy of the data. Due to errors in the updating process, periodic, expensive, and time-consuming GPS sign resurveys were required to keep the database accurate and current.

In May 2000, the Road Maintenance Division implemented a new method of sign inventory maintenance using some of the latest, yet very affordable, mobile GIS software and hardware products.

The decision was made to try a new Esri portable GIS software product, ArcPad. This software was installed on older laptop PCs and given to Sign Shop personnel. The purpose was to evaluate the feasibility of accessing a digital map in the field. The resulting appraisals were optimistic but the laptops were bulky, slow, and difficult to view in outdoor lighting. ArcPad was installed on a Cassiopeia E-115 Pocket PC with 32 MB of RAM and a color display using Windows CE for further evaluation in the field. Reports were much more enthusiastic. The pocket PC was lighter, faster, and easier to use and had a display that was far easier to view in outdoor lighting.

 Joe Martin updating sign information
Joe Martin of Boulder County Road Maintenance updates sign information on one of more than 7,000 signs in the field using ArcPad and a Cassio-peia Pocket PC.

Because ArcPad has the ability to edit data, it seemed logical to train Sign Shop personnel to use that function while in the field. ArcPad is also able to use forms for information update. By designing drop-down menus, data entry was standardized and the ease of use for employees was enhanced.

Now Sign Shop personnel are able to carry with them a pocket PC containing an accurate and current digital map of more than 7,000 road signs with all the necessary information about each sign including type and location. Employees are able to update information about an existing sign in the database while looking at that sign. Missing or incorrect signs have become much easier to locate and replace. Roadside sign inspections are more complete and accurate. Mistakes that an employee notes in either the inspection procedure or the information in the existing database are corrected.

The data that is collected in the field can be downloaded directly from the pocket PC, eliminating the need for data entry from paperwork. This data is transferred via a network consisting of Compaq desktop PCs and servers. It is then processed to update an existing master sign database residing in the central office. An updated sign shapefile is sent back through the network into the pocket PC for the user to have access to the most current version of the digital "live" sign map. The digital map is generally current to within one week or less.

Employees are also able to use the information to help locate missing signs. Prior to implementation, one missing sign had been searched for unsuccessfully on several occasions. Using ArcPad, an employee simply measured on his pocket PC the distance from a nearby sign to the installation location of the missing sign. He walked to that location and found the sign laying several hundred feet down an embankment. Instances such as this occur on a regular basis.

Employee mileage for sign replacement and inspection has been greatly reduced. Paperwork and data entry errors are also significantly reduced. The Road Maintenance Sign Shop presently has three sign technicians using this system resulting in a savings of one to two hours a day for each employee. The time that is saved can be spent performing more maintenance work in the field resulting in an increase in overall productivity. Time savings for GIS personnel due to the elimination of data entry from paperwork are approximately two hours per week. The $3,466.95 cost of implementing this new procedure included three Cassiopeia E-115 Pocket PCs, three copies of ArcPad, and training for three employees in the use of the software. The program paid for all start-up costs within a two-month period. Total savings were more than $20,000 per year.

One of the unexpected results is that the Sign Shop employees have developed a stake in the success of this program and feel some ownership and pride in it. Another result is that road signs in the County have become extremely accurate, providing the public with the level of safety that was originally engineered into a section of road.

Using Esri's ArcPad with a pocket PC can be summarized as providing inexpensive, accurate, timely, and reliable information updates while supplying users with the necessary information in the field for performing their tasks at the highest level of accuracy and efficiency.


This program has been recognized at both a local and national level. John Mosher received Boulder County's Annual Innovation/Achievement Award. In addition, the Boulder County Road Maintenance sign inventory program, "Road Sign Management Using GPS & Pocket PC Technology," received a National Association of Counties (NACo) annual Achievement Award-2001, one of the highest honors that a county government can receive.

For more information, please contact John Mosher, Boulder County Road Maintenance (e-mail:, tel.: 303-441-3962).

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