Catastrophe on Mildred Lane Shows Problem with Road Design

August 2020

Front page
today

The front page today has news on sentencing in a traffic fatality from last summer.

It is framed up as the story of poor teenage judgement that leads to catastrophe and grief.

[The driver] told police he was driving too fast and that he saw the stop sign [at Liberty] and knew it was an intersection but didn’t see any headlights, so he didn’t stop, according to the state’s memorandum.

It certainly is an instance of catastrophically bad judgement, but there is also more.

Mildred Lane had a posted speed limit sign of 35 miles per hour less than a mile from the Liberty Road intersection. Investigators determined Goodwin was driving more than 60 mph through the intersection.

Mildred Lane is overbuilt. It is built to our contemporary urban standard for a minor arterial, with bike lanes and sidewalks, and a continuous center turn pocket. The car lanes are a foot or two wider than they need to be. 10 feet would be sufficient, and is safer. Even with occasional medians that interrupt the turn pocket, the street is three lanes wide. The terrain is hilly. The posted speed is high for a residential neighborhood.

Current design standard (TSP, Jan. 2020)

This design and the posted speed of 35mph practically invite speeding. It is comfortable to go faster than the limit.

At the park it's wide and zoomy, signed for 35mph

Bryan Johnston Park is at the top of the hill, a bit of a table top, at the intersection with Lone Oak. A median refuge was built in the enhanced crosswalk because clearly the cross section of the road was too wide and zoomy for safe and comfortable walking. They knew this!

Crosswalk and refuge on Mildred Lane (2013)

Westbound on Mildred Lane, after the bit of plateau with the park, it is mainly downhill to the intersection with Liberty. It would be especially easy to pick up speed, and the curves may suggest a race car mentality, hugging those curves. 

In 2013 a nearby resident said in a comment here:

Mildred Avenue..."overbuilt" is a really apt description. As a consequence of this, speeding cars is a constant problem. 50 mph is not unusual, even though the posted speed limit is 35. It is also a favorite for "hill hopping" between Sunnyside and Lone Oak, usually in the evenings and late at night.

Here we are in 2021. There is on Mildred Lane a consistent and chronic problem with speeding, and the road itself invites this. By our road design, and the implied design speed, we make it too easy for teens to make bad decisions that lead to calamity. The design does not erase the poor judgement by a teen driver, but it is a contributing ingredient. It makes disaster more probable and increases the severity of disaster when it happens. Other teens and young adults involved in hill hopping and speeding may have been more lucky and avoided a crash, but the odds suggest disaster will happen again.

Mildred Lane needs traffic calming so that speeding and hill hopping is just simply not possible here. More generally, throughout the whole city we need to reassess and adjust our prevailing standards, including road design standards, for speed and speeding.

Mildred Lane has a design problem

Recently, more on speed and speeding:

• On evidence from photo enforcement, "Police Surprised at Amount of Speeding" (2020)
• On the doctrine of 85th percentile speed and road design, "Latest Dangerous by Design Report is Good Context on 17th and 45th Street Speeds" (2021)
• On the evidence here and from other cities on speeding, "Critiquing Photo Enforcement on Red Lights and Speed" (2021)
  

Update, August 13th, 2022

The paper reports on a lawsuit. It appears to leave lane width and road design untouched, and to criticize signage, visibility, and vegetation trimming mainly.

August 11th