TO:                 Mayor William F. Martin, Jr.

                                    And

                        Members of the Lowell City Council

FROM:           Bernard F. Lynch, City Manager

DATE:            September 19, 2007

SUBJECT:       MOTION OF 9/11/07 BY COUNCILOR RODNEY ELLIOTT

CITY COUNCIL REQUEST THE CITY MANAGER INVESTIGATE THE PLAUSIBILITY OF A PILOT PROJECT TO INSTALL SPEED HUMPS AT SCHOOL CROSSWALKS

In response the above referenced motion, Jeff Gomes, Transportation Engineer has researched the appropriate material for the motion in question and made some conclusions.  To understand the design, purpose, and effect of speed humps it must be explained in detail.

Speed humps have a design speed of 20 mph which differ from what people know as speed “bumps” which require a very low speed of 5 mph or less and are allowed on private property but not on public ways. Speed humps are lengthier than bumps and are easier to navigate that the bumps. Speed humps are commonly used in school driveways and are appropriate for this location because vehicles in school driveways during school hours should be traveling at a lower speed.  If a speed hump were installed anywhere other than within a school driveway, school zone or appropriate high pedestrian area, it could have negative and sometimes dangerous results.  Humps that are inappropriately located slow traffic when not necessary such as commuting hours and times outside of school hours.  They also increase rear-end collisions due to motorists not expecting the raised asphalt in the public way.  They cause wear and tear to vehicles, and are hazardous to motorcycles and bicyclists.  Speed humps cause an increase in noise due to the braking and acceleration of vehicles as well as increase pollution.  There are issues concerning snow removal and snowplows often damage the speed humps thereby causing a constant maintenance issue for both the speed hump and the plow equipment.

According to the MassHighway Project Development and Design Guide, speed humps can be appropriate on local roads if designed properly.  On higher-classified streets such as major collectors or arterials the design speed of a speed hump (20 mph) would not be appropriate or consistent with the function of such streets.  Speed humps are generally safe to install only in school driveways, and high pedestrian areas provided they are properly designed and emergency response friendly.  For emergency response, speed humps are designed with cut-outs where the fire engine or bus wheels travel (which is wider than a standard vehicle), meaning a car or truck would have to drive over the hump whereas an emergency vehicle or bus can drive through it without slowing to 20 mph.

Where there is discussion about speed humps at school crosswalks as mentioned in the motion, the proper term and installation method would be a “raised crosswalk.”  Raised crosswalks are very much like speed humps except that the top part of the hump is flat thereby making it easy for pedestrians to walk over.  If such a traffic calming measure is used it should be supplemented by a fluorescent yellow-green sign (W11-2) and arrow (W16-7p) on the right hand side of the roadway to alert passing traffic of the raised surface as specified in the Manual on Uniform Traffic Control Devices (MUTCD).  It is also desirable to provide a textured or stamped surface to distinguish the walk area of the raised crosswalk.  This is a common application used in many communities.

The plausibility of installing speed humps or raised crosswalks in school driveways is worthy in that they provide a good traffic calming measure.  However, careful consideration must be given to their placement in proper location(s) and proper design as detailed in the MassHighway Project Development and Design Guide, page 16-32.  The approximate cost of installing either a speed hump or raised crosswalk, including necessary signage, is $1,500 - $3,000 depending on choice of materials for a textured crosswalk.

If you have any questions regarding this, please let me know.

Thank you.