There is a big interchange upgrade project going on at Sante Fe and I-25 which has been under construction for about 2 years now and is showing signs of nearing completion. The ramp from northbound Sante Fe to north bound I-25 is a marvel to behold: 2 lanes wide and several stories high. The view from the top is magnificent.
Up till recently one could get up to 40-50 mph, hit the ramp, motor over the top and seamlessly merge into I-25, first the left lane, then the right. The only possible slowdown was the city of Denver setting up a photo radar truck at the beginning of the ramp to enforce a 25 mph speed limit which meant you had no momentum to get over the ramp.
The photo truck is no longer needed. Some genius somewhere decided that all the ramp traffic would merge together into one lane before reaching I-25, drive alongside the freeway traffic for about 1/2 mile, then merge onto the freeway just as the next on-ramp began dumping more traffic into the right hand lane. Speeds approaching the new ramp are now down to 5-10 mph beginning about 1/2 mile before you get to the ramp and continuing past the Alameda on ramp some 1/2 mile beyond.
The good news is that Denver is no longer raking in the revenue with their photo truck except on weekends when there is less traffic.
Here's a situation where a tagger with a can of white spray paint could ease a lot of congestion and add the title of "traffic engineer" to his business card. I wonder how long it will take for someone with the authority to actually lay down paint to figure this out.