Mailbox support crashworthiness standard update
By: Mark Vizecky, State Aid Operations Engineer
A Valentine Riddle: I hold heartfelt wishes from your Valentine, but I’m breaking so many hearts this year.
Answer: Your mailbox or more appropriately the mailbox support.
What’s causing all the negative fan mail? The implementation of updated crashworthiness standard. The new design requires the addition of an underbar to the existing swing away design (highlighted in gold). Several different versions were tested, but only the current standard plate (9350C) could meet the omnidirectional requirements of MASH (Manual for Assessing Safety Hardware). Insert frowning face emoji. More on MASH at https://www.roadsidepooledfund.org/mash-implementation/.
A few things to contemplate, while taking deep cleaning breaths to keep the Hulk at bay. Today, MASH only applies to routes on the National Highway System (NHS), totaling 88.613 miles of local roads in Minnesota. The existing MnDOT stand plate (9350B) (PDF), can still be used on local projects not on the NHS and off MnDOT Trunk Highway Right of Way.
Each agency should place a memo in the file stating the intension to use the existing standard plate detailing when, where and why it will be used. Your justification on why could include crash history/performance with existing detail, the limited ability for a small passage car to strike the support perpendicular to the roadway on a narrower two-lane road, or lower speed roadway with curb and gutter.
On to referencing the existing standard plate in a plan set, this example is shared with permission from our friends in D3 State Aid.
The current version of yourself is asking a great question, that a future version of yourself will be dealing with. What will we do now that MnDOT is now no longer maintaining the existing standard plate (9350B)? Great point (high five current you), as a historical detail, no updates or edits will occur. Collective local agencies in Minnesota should investigate how best to move to towards MASH compliant devices (hint LRRB).
Please send all questions on handmade Valentine to Mark Vizecky, State Aid Operations Engineer at mark.vizecky@state.mn.us or 651-336-5969.