Dislodged manhole cover in O'Neill Tunnel strikes car, kills driver

[roadman]

MassDOT presently conducting inspections of all manholes and grates in Metropolitan Highway System tunnels:

http://www.boston.com/news/local/massachusetts/2016/02/12/crash-neill-tunnel-causing-delays/ufM1z5oBnn333zdbUDX0LP/story.html?p1=ClickedOnBreakingNewsBox

[Pete from Boston]

What kind of force at what angle could send a manhole cover airborne?

[The Ghostbuster]

I've never heard of a manhole cover in a tunnel before. Are they used for maintenance purposes?

[cpzilliacus]

I've never heard of a manhole cover in a tunnel before. Are they used for maintenance purposes?

In most tunnels, there needs to be some sort of access to the sump at the lowest point in the tunnel. In some tunnels, that is apparently with a manhole. 

[SidS1045]

I've never heard of a manhole cover in a tunnel before. Are they used for maintenance purposes?

As the linked article stated, "The manhole that caused the crash covered a storm drainage system and was last inspected June 12, 2014."

[bob7374]

Here's a link to the official MassDOT press release about the incident:
http://blog.mass.gov/transportation/massdot-highway/massdot-highway-administrator-tinlin-statement-on-vehicle-struck-by-manhole-cover/

I had to travel through Boston on I-93 today for a lunch meeting on the North Shore. Because of the on-going investigation in the southbound lanes, traffic was still backed up into Medford on I-93 South at 11:30 this morning. Coming back (via the Tobin Bridge) the VMS displays in the Big Dig Tunnel and and further south warned of work crews in the roadways, but I didn't see any. I did drive by the location of the manhole and saw all the lines spray painted on the pavement by the accident investigators. Since I frequently drive I-93 it's sobering to think if this had happened at another time, I could have been that driver (a teacher at a public school in Milton).

[briantroutman]

The only scenario that I can imagine is that the manhole cover wasn't replaced correctly and was wedged unevenly on another object, then a passing vehicle put enough pressure on the right point and flipped it up, tiddlywink-style.

[mass_citizen]

MassDOT has published a new policy requiring bolt down manhole covers on all projects. This is in addition to the bolt down catch basin policy implemented some years ago.

https://www.massdot.state.ma.us/Portals/8/docs/EngineeringDirectives/2016/E-16-003.pdf

[roadman]

MassDOT has published a new policy requiring bolt down manhole covers on all projects. This is in addition to the bolt down catch basin policy implemented some years ago.

https://www.massdot.state.ma.us/Portals/8/docs/EngineeringDirectives/2016/E-16-003.pdf

A clarification - the new requirement to bolt down manhole covers only applies to roadways with speed limits of 45 mph or greater, and not "all projects".

[formulanone]

The only scenario that I can imagine is that the manhole cover wasn’t replaced correctly and was wedged unevenly on another object, then a passing vehicle put enough pressure on the right point and flipped it up, tiddlywink-style.

Sounds a lot like this race, but those particular cars also produced an enormous amount of underbody pressure (downforce) against the road surface.

Skip to 13:00...thankfully, he was only slightly injured.

https://www.youtube.com/watch?v=7-21jsFAc0I

[mass_citizen]

MassDOT has published a new policy requiring bolt down manhole covers on all projects. This is in addition to the bolt down catch basin policy implemented some years ago.

https://www.massdot.state.ma.us/Portals/8/docs/EngineeringDirectives/2016/E-16-003.pdf

A clarification - the new requirement to bolt down manhole covers only applies to roadways with speed limits of 45 mph or greater, and not "all projects".

My apologies...my use of the term "all projects" was referring to the fact that the directive applies to all active construction projects in addition to those in design. You are correct with regard to the speed restriction.

It is interesting to note however that MassDOT's policy with regards to bolt down/hook lock catch basins has not changed and applies to all roadways and projects regardless of speed.