Eric Wood is our featured associate this month. [...]
GIS has a multitude of applications in planning and engineering. Right now, we are working with the Regional Planning Commission of Greater Birmingham (RPCGB) to develop a linear referencing system. It’s an interesting project that has the potential to greatly enhance RPCGB’s ability to manage the Birmingham region’s transportation improvement program.
A linear referencing system is basically a system in which the locations of features are identified by a relative measure along a linear element. In this case, we’re using road center lines.
Our first task was to develop the route data set (or route feature class) and group of lines that define all the routes in the Birmingham region, like I-20, US 78 or US 11.
Once that core route data set is developed, we can associate the different types of data with it, such as functional classifications, project databases, transportation plan projects, speed limit ranges, pavement conditions, pedestrian/bicycle lanes, mile post differences and more. We create a table that associates those projects to the route so they don’t have a different line database for every piece of information.
For example, if a project goes from mile post 1 to mile post 5, that’s all they have to put in the table. The GIS can take that table information and project it onto the map as a line. RPCGB will maintain the data in table format, but the data can be projected to the map based on the route system that we’re developing as the core data set.
If they make a modification, they only have to make it to that route data set instead of changing multiple different line data sets to accommodate just one change in a road. If a road is relocated or the route is changed, all they have to do is change that route data set and then the tables update according to those changes. This will help them save a lot of time.
The project is over halfway complete now, and we’ve finished the core route data set. Currently, we’re in the process of giving the RPCGB an updated data set of functionally classified roads based on new classification criteria provided by the 2010 census for urbanized areas.
Once we’re done, we’ll do an installation and training with RPCGB and provide them with their own user guide. We expect the project to be complete by the end of February and result in a more accurate and integrated mapping system.
We’ve enjoyed working with RPCGB. They are a great organization that provides economic development services and multiple initiatives for six counties and 84 communities throughout central Alabama.
Sain Associates, Inc., is headquartered in Birmingham, Alabama, with offices in Cullman, Alabama, Pulaski, Tennessee and Mandeville, Louisiana. Sain is a site engineering, traffic/transportation engineering and planning and land surveying firm with experience in more than thirty states.