To Build a Bridge Several years ago, I wrote a four part series about the story of the Stillwater Bridge across the St. Croix River. Part 1 covered the project from 1950s promises to build a high bridge and get traffic well away from downtown up to the point the original iteration of the 1980s proposal was […]
The Dawn of Light Emitting Diodes (LEDs) Previously I covered the cobrahead streetlights of the Twin Cities. Well, they’re almost gone. The thousands of high pressure sodium MnDOT lights on the freeways have been converted to LED (light emitting diodes) and the 90,000 Xcel energy lights are in the process of being converted. So it’s […]
Urban planning “locker room talk” — decrying sprawl, stroads, subsidies and other S words — doesn’t advance the dialogue, our author asserts.
This is Part 2 in an overview of overhead street lighting. Earlier we talked about NEMA lights, which are still commonly used in St. Paul. Today we cover some of the newer form factors. “Clamshell” Street Lights Because of their large circular filaments, incandescent street light bulbs needed to be mounted vertically. But no such […]
The Orange Line in Jeopardy Dakota County has decided to leave the CTIB (County Transit Improvement Board). The CTIB allegedly retaliated by refusing to fill a $12 million gap from the failed bonding bill with CTIB funds; this puts the Orange Line in jeopardy as the bulk of the funding ($120 out of $150 million) is expected […]
An event predicted by many finally occurred: the first fatal crash in an electric self-driving car, on May 7 in Florida. That crash was followed soon by two more non-fatal crashes, one in Pennsylvania on July 1 and another in Montana early Sunday morning. Tesla’s stock fell and the media is having a field day predicting the death of […]
Previously I wrote about streetlights, with a special emphasis on the freeways since these were about to be converted to LED. Now Xcel Energy has announced 100,000 local streetlights in its service area will be converted, so it is time to look at some of these. The NEMA Lights In the early days, every manufacturer […]
The first two parts of this series dealt with warrants and justifications for traffic signals. Here the series concludes with a discussion of warrants and justifications for signs and other traffic control devices. Justification for Stop Signs Let’s go to the Minnesota MUTCD; section 2B.4: .03 YIELD or STOP signs should be used at an […]
Analyzing a Corridor Previously we went into what the warrants for signals were and went through some examples. So now let’s look at all the signals on a corridor. I picked South Lyndale Ave (with the exception of the signal at the ramp to MN 62, which is Mn/DOT operated. I’m going to cheat and just […]
Previous articles of mine have covered just about every facet of traffic signals, including how they work, how timing and phasing are set, and even how to identify who made a particular signal. But what about how it’s decided whether to add or remove a signal in the first place? That is done through “warrants” […]