Save My Child -- Hump My Street

When speedhump zealots want their streets humped they conjure up imaginary images of children splattered on auto grills.  [And, local TV "reporters" eat it up.]  Such irrational, emotional outbursts appear are the major basis of support for speedhump programs.  Let's try to bring some perspective to these preposterous claims.  

Three pedestrians younger than15 are killed in Houston each year.  ('96-'97 data from Texas DPS Accidents Records Bureau, the last years for which we have data).   To be clear, this means a total of 3 children are killed on Houston's streets each year.

Houston does not break this down by type of street, but Austin, Texas does.  Austin's percent of deaths on residential streets is roughly 10% of total pedestrian deaths. 

Applying Austin's rate to Houston yields 1/3 of one child killed on Houston's residential streets each year -- that's on all residential streets in the entire city. 

This means if:

  1. Every residential street in Houston were humped end-to-end, and

  2. Humps prevented every death;

The most we could save is 1 child every 3 years -- in all of Houston.  

But, all of Houston's streets aren't humped.  About 600 of Houston's 48000 streets have humps, and of these, only a portion of each street is humped. 

It's difficult to get data from the City, so the following estimates are rough. 

Roughly eight-tenths of one percent (0.8%) of Houston's residential street-miles are humped. 

Houston has the most extensive speedhump program in the nation.  Yet this estimate says, at best, Houston's speedhumps can only hope to prevent about 24 ten-thousandths of one death per year (0.8% of residential streets humped TIMES  0.3 children killed on residential streets annually). 

Said the other way 'round, if you assume speedhumps could guarantee to prevent all deaths of children on all humped streets, it will take 425 years for the current program to save one child. 

The Coalition believes speedhumps cost lives instead of saving them -- see our article on this -- but, it's obvious humps can't guarantee children's safety.  For example, backing out of driveways is a common cause of child traffic deaths on residential streets.  So, a breakdown of the real causes would show it will take longer than 450 years to save one child -- probably much longer. 

Because Houston doesn't record which deaths are on residential streets, no one can make more accurate estimates, but the above estimates based on Austin's pattern are probably close, and probably typical of any large city.

So, back to "Hump My Street and Save My Child."  To save just one child on a particular street it would take about 250,000 years.  To save a particular family's child on that particular street would take something like 12 million years.   

 

Endnote:   As we continue to say, it's very unlikely speedhumps save any lives -- for the many reasons explained in this article.  But, for those who still believe humps save lives, and feel "Even one child saved in 400 years is worth any inconvenience;" they must address the fact that the lives lost from delayed fire and emergency medical response over 400 years will far-and-away exceed this imaginary one life saved.  Speedhumps kill.  See the clear and compelling evidence in this article.