Mapping the Construction of I-485



The geography of I-485’s construction begins in the south of the city. This immediately starting providing relief for the increasing volume of traffic due to the growth of the suburbs in south Charlotte and near the South Carolina border. The next order of business was connection the attractions, university, and high population suburbs in the northeast of the city. Finally, the west quadrant of the road was completed, alleviating traffic on Billy Graham Parkway around the airport and connecting the I-85 – I-77 bypass in the northwest.

I-485 broke ground in 1988 and was a completed beltway in 2015. It took 27 years to build 67.61 miles of the interstate at a rate of 2.504 miles per years. Compared to other beltways, this is a relatively lengthy period of construction.

I-270, a beltway around Columbus, Ohio took 13 years to build, being completed in 1975. It equates to 4.228 miles per year construction. This partially due to the stimulus provided by Federal-Aid Highway Act of 1956 championed by Dwight Eisenhower which provided resources for state governments to jumpstart construction on the interstate system that we know today.

I-465, the beltway around Indianapolis, broke ground in 1959 and, drawing from the highway stimulus, its 52.79 miles were completed at a blistering 4.799 miles per year.

Constructing this collage of maps in ArcMap provided exposure to some of the more intermediate functions of the design toolkit. After acquiring the interstate highway data from the Mecklenburg Open Mapping portal, 17 data frames were created to represent the 17 phases of I-485 construction according to the history section of the I485 article which cites The Charlotte Observer.

In the layout view, I navigating to the data frame tab in the properties menu to set the extent of each map to mimic the extent of the first data frame I set manually. This, I believe, was the optimal design choice to map the different phases of construction. This is the shortcut for manually adjusting each map’s extent which would have taken a considerably longer time to accomplish. It also ensures consistency with the design.

I enabled grids in the layout view which is nice for checking the alignment of elements at a glance. Also, I adjusted the page layout to allow a custom margin (20 inches by 8) when exporting the map as an image.

Finally, I made use of the distribute tool which is in the right click menu of the layout view. This easily allowed me to align all the rows automatically, eliminating the need to manually align each individual data frame. Each row was aligned horizontally and then vertically to ensure each was in the proper position. The same method was used for the text above each frame. Some instances of the text, however, needed to be adjusted manually.

This was a fun exercise. I could take it further in the future by color coding the map according to how many lanes each section has. This would allow the presentation of lane widening projects which are still ongoing on 485 as well as many other beltways and interstates around the country. It would be interesting to compile all the phases of construction into a short movie or .gif. This would require going back and upscaling each data frame individually to get a useable resolution.

Reflecting on the design, I’m not sure how to deal with the text labels. Looking at a glance it can be confusing which map a label is referring to, the map above or below. Perhaps I could have put the label in the middle of the beltway to clarify exactly what map is being labeled. This might have allowed each map to be bigger. This might detract from the negative space in the middle of the beltway and give a cluttered appearance. The use of lines might have been appropriate to border each map with its label. This might have made the map too busy. I’m happy with how it turned out. It’s always good to consider the alternatives.