Traffic Report: Snapshots In The News

Illustration abstracts what is needed to present picture of rush-hour traffic hassles

Part of map illustrating present traffic volume on western Portland Or freeways, in the 2 Oct 05 Sunday Oregonian

Traffic congestion is a problem which plagues every major city in America. We all must get from there to here and there again in the course of a day, doing the evergreen dance we call the commute. Future planning must take into account not only where people are going now, but where they may be going in years to come.

Portland, Oregon’s The Sunday Oregonian takes up the point in a front page article titled “Think the commute’s bad now? More jobs may mean more jams”, written by James Mayer. The article takes a look at increased pressure on Portland’s freeway network which may be brought on by future economic growth, particularly those of citizens commuting to jobs. The illustration above (by Oregonian artist Steve Cowden) is meant to be a depiction of traffic conditions at 5:30 p.m. on a recent Thursday–traditionally, the start of rush hour.

Maps in newspapers are used to make points, and this one in particular to not only make a point but to support and reinforce the point made in the article. Maps like this one also interest the reader in continuing into the article with the aim of understanding the map’s message.

Getting to the point

Comedian Stephen Wright once said “I have a map of the united states…it’s original size… it says one mile equals one mile.”

The challenge in producing a map that makes the point is context and relevant information–what to leave in, what to leave out, and how to represent what is deemed necessary. The traffic map from the newspaper provides a window through which we can guess about the aims of the maker.

It must contain enough geographic detail to easily allow the reader to quickly recognize it for where and what it is, but not so much that the actual informational payload is obscured. That payload–the freeways–must also exist within those details but be the star of the piece.

The detail, then, is winnowed down to what’s necessary: a dark area representing the approximate urbanized area of greater Portland, finely stroked lines representing roads that are chosen based on two criteria: first, they are major arterials and are included if, and only if they are secondly signed highways. Indvidiual cities within the conurbation are indicated by a classic dot-and-name. The type face is chosen to be in concert with the rest of the newspaper’s headline type, providing a link unifying he map content with the rest of the paper.

The freeways, the whole point of the piece, are vastly oversized and backed with a drop shadow, making them not only easily visible but actually pushing them up off the 2D surface, giving a perception of being closer to the reader. Thus primed to be viewed, the informational punch of the map is provided by color fill in the freeway symbols. In a clever touch, the colors correspond to three speed ranges which are mapped to something very familiar; the three colors of the common traffic signal–green for fastest speeds (50 mph and over), amber for the middle ranges (averages 25-50 mph), and red for the slowest areas (zero to 25 mph).

Viewing the map along State Route 217 we can then draw various conclusions about what we may expect in suburban Portland at 5:30 p.m.: slow and go traffic, where you may find oneself braking as often as accelerating, and becoming very slow indeed at one point.

Additional context is provided by the average daily traffic figures, called out in gray boxes pointing to the appropriate road. Those are busy roads!

Perhaps the most intriguing thing of the map is the white areas on the roads. These are areas for which no data was available from the source. These, somewhat curiously, include places on freeways where two roads come together and sections of one freeway directly across from another very busy section. One can make educated guesses about such areas, but one can’t be certain about them.

Getting to the Source

Traffic Conditions snapshot map by Oregon Dept. of Transportation (courtesy ODOT)

The source cited by the artist is the Oregon Department of Transportation (ODOT), particularly the ODOT website www.tripcheck.com/pages. Going there at any time of day or night provides a link to the map shown on the left.

Seeing what the artist had to work with gives an instant appreciation of the artistic choices he must have had to make in order to produce the illustration. It becomes apparent that the areas marked “No data” on his map were so because his source had no information to give him. It also serves as a credit to the artist as to how well he was able to give graphic punch to the map. The ODOT graphic is informative but rather flat in comparison. Also evident is the judiciousness with which contextual details were chosen to support but not overwhelm the important information the map contains.

News maps are cases of abstraction in the extreme. They must be; there is a limited amount of space to tell a story and maps are more often meant to support text rather than to be the focus of attention. Done well, however, they can quickly inform and support a story, adding a personal spatial dimension to the reader’s experience.

This is a good example of the art, and over time I hope to bring good as well as bad examples to the fore.