Mike on Traffic

Albeck Gerken tests the accuracy of portable traffic counters (Jamar - Miovision - Wavetronix)

My friends over at Albeck Gerken have done their own independent testing of portable data collection equipment.  They tested Jamar's Trax 1 road tube counter, Wavetronix's microwave detector, and Miovision's video system.  All three technologies seem to count to 95% plus accuracy.  Check out their white paper for more information.  They are very complimentary of Miovision in the paper. 

Roadway Safety Improvements – Curve Warning Signs

The Federal Highway Administration has decided to study a host of low cost safety devices to determine whether they do in fact work.  Surprisingly, the effectiveness of many types of warning signs has never been studied.  The effectiveness of providing more conspicuous signing and lane markings at roadway curves was recently analyzed in FHWA Publication Number FHWA-HRT-09-046.  

Crash data for horizontal curves on rural, two lane roads was collected in Connecticut and Washington.  Connecticut has recently been upgrading their existing curve warning signs to fluorescent yellow sheeting as well as adding fluorescent yellow curve warning signs to locations that previously had no curve warning signs.  Washington has recently focused on installing more chevron curve delineation signs (type W1-8), either adding chevrons to previously unsigned curves or adding more chevrons to previously signed curves.  Crash data was collected on roadways with the improved curve warning signs and compared with crash data from similar roadways where the improved curve warning signs had not yet been installed. 

The most significant safety improvements were related to crash reductions during dark conditions and the reduction of injury plus fatal crashes.  Crashes on curves during dark conditions were reduced by 35.3% in Connecticut and 24.5% in Washington.  Injury plus fatal crashes were reduced by 25.2% in Connecticut and 18.0% in Washington.  These findings were found to be significant at the 95-percent confidence level, meaning there is a strong correlation in the statistical data between installing curve warning signs and reducing these types of crashes. 

An economic analysis was also done on improving curve delineations with warning signs.  It was found that installing curve warning signs on rural, two lane roads is very cost effective with a benefit-cost ratio exceeding 8:1.  A ratio of 2:1 or better is typically considered a good investment.  In short, improving curve warning signs is a very good idea.

St. Paul Port Authority's Redevelopment of 3M's Former Saint Paul Campus - Spack Consulting hired for Traffic Study

The St. Paul Port Authority is redeveloping 3M's former 46 acre campus on the east side of St. Paul (read about it on the Port Authority's site here).  This is in line with their mission of assembling and cleaning up polluted and/or underutilized inner-city land.  Typically the Port Authority sells the cleaned up parcels to expansion minded businesses for $1.  The Port Authority works hard to create jobs on the east side of the Twin Cities.

We've been hired to do a traffic study for the redevelopment.  We'll be analyzing two development scenarios (+/- 700,000 square feet of new buildings along with the potential reuse of some existing buildings) and determining the traffic impacts of the redevelopment on about 30 intersections.

This is a great project for all involved and I'm excited to be part of it.  I always enjoying working in St. Paul - I was an intern with City while I was in college.

Help - people are speeding in my neighborhood and I need a stop sign!

I've had two calls this fall from private citizens wanting me to help them convince their city engineers to install stop signs in their neighborhoods.  Up until a month ago, I thought I left this topic behind when I left Maple Grove.  Here is the gist of how I responded to the request.

All way stop signs only work when there is heavy enough traffic at the intersection so people need to stop (the rules are below from the MN Manual on Uniform Traffic Control Devices).  Otherwise your neighbors get conditioned that there is no crossing traffic and they start blowing the stop signs because there isn’t a reason to stop.  This phenomenon is well documented (the same way people drive 65 mph on most highways unless a police officer is present, then everyone magically goes 55).  I personally studied this in Maple Grove when I was on the staff there.  We found about 20% of people didn’t even touch the brakes for the stop sign.  This is very dangerous for everyone who goes through the intersection.

The only way to control speeds is with traffic calming measures, which are well documented here - http://trafficcalming.org/.  I can do a full study on the intersection and come up with a recommended solution, if there is a problem (as defined by high traffic volumes, high speeds, or high numbers of crashes).  The city engineer will probably collect the traffic volumes and come back saying you do or do not meet the criteria below.

 

p.s.  I like the leaves someone put on the stop sign post.