The other day I was driving north on C-470, and I wanted to go east on the 6th Avenue Freeway towards downtown Denver. That movement is shown on the map below:
I rarely drive that direction along C-470, but I have lived in Denver for a long time, and I'm pretty confident about knowing my way around. So as I approached, I was quite certain that I would need to follow eastbound I-70, and that the exit for eastbound US 6 would come up shortly after that.
But then I saw this: the first sign that references US 6 on northbound C-470:
The panel on the left has a US 6 shield with no directional modifier. In other words, it doesn't specify "WEST US 6", so the implication is that both directions of US 6 (east and west) will need to get in the left lane. The panel on the right does not say that eastbound US 6 traffic should follow I-70. So at this point I started doubting my plan and questioning my memory. "If I follow eastbound I-70, maybe there is something that would prevent me from being able to access eastbound US 6..?"
The next sign after that references only westbound US 6; it does not provide any info for drivers who want eastbound US 6:
The sign at the exit gore repeats the earlier information: all US 6 traffic should be in the left lane. Again, there is no mention of US 6 on the right-hand panel:
So I thought, "Well, I guess my memory is wrong, I better follow the signs." But shortly after doing so, I quickly realized that I hadn't been wrong: I should have followed eastbound I-70 after all. As it was, I reached US 6, turned east, and soon passed through the US 6 / I-70 interchange. But if I had used I-70, I would have been at that same interchange a couple minutes earlier, and I would have stayed entirely on freeways. Following the signs causes eastbound US 6 travelers to pass through a couple traffic signals, lose a couple minutes, and go about a mile more than necessary.
Even if I had done it correctly and taken the exit for I-70 traffic, the next sign still does not provide any info for drivers wanting to head east on the US 6 freeway:
Now let's think about this for a minute. Let's take all drivers who are both a.) heading north on C-470 and b.) exiting to any direction on US 6. Out of all drivers meeting those criteria, what percentage do you think are heading east on US 6 towards downtown? I don't have the data, but I bet it's the vast majority. I would guess it's something like this:
The way it stands now, signage directs all US 6 traffic to stay on C-470 (via the route shown in purple above), even though that route accounts for only 25% of US 6 traffic. The remaining 75% of US 6 traffic should follow route shown in green above, yet currently there is no signage directing US 6 drivers along that route.
I realize it is sometimes desirable to reduce information overload by keeping highway signage simple. But sometimes oversimplification can be misleading, and the current signage along this segment of C-470 is one such example. With just a few minor changes, these signs could be made much more informative for the majority of US 6 traffic movements. Let's take another look at the first photo on this page:
Again, the left panel is misleading because it implies that all US 6 traffic should stay to the left. And it is misleading for another reason: instead of a control city, the left panel references a roadname (6th Ave). Since 6th Ave runs both east and west from the junction with C-470, drivers cannot glean any further clarification from that. So it would be a huge improvement to change the left panel to something like this:
That provides clarification that only westbound US 6 traffic should be in the left lane. It provides further clarification by using the city of Golden as a control point. But what about all the drivers who want to follow eastbound US 6? After all, that is the most common traffic movement here, so it should definitely be signposted. That is why some additional changes were made to the right-hand panel above. The following image makes it easier to compare the current sign with the proposed sign:
If those changes were made to the two overhead sign bridges on northbound C-470, then 95% of all traffic exiting to US 6 would be well-served. One might ask, "What about the 5% of drivers who need to use the one-mile segment of US 6 between C-470 and I-70?" The control point of "Golden" would be helpful for them, but other than that, my thought is that no additional signage is needed for those drivers. If a choice needs to be made between serving 25% of the traffic vs. 95% of the traffic... well, frankly that's a no-brainer.