Metal Beam Guard Fence - Sandy Lake Road BridgeKeith,
During one of our recent meetings you mentioned something to me about
whether or not a metal beam guard fence (or crash cushion) should be
provided at the western end of the pedestrian rail on the bridge. Since
that conversation I've re-visited this issue internally with our TxDOT
team and wanted to provide you with some additional thoughts/comments:
At the time the Sandy Lake Road plans were issued for bid (03/13) and
construction (06/13) the minimum horizontal clear zone requirement was
1.5 feet. As of December 11, 2013 TxDOT changed to a minimum of 4 feet.
See attached info from TxDOT Roadway Design Manual.
Our design met design standard at the time of issue, but that the
industry has since moved to more conservative clear zone widths.
If desired, the guardrail can be added to align with the face of curb
(see last page in PDF) and then transition to the bridge rail.
Let’s discuss tomorrow.
Thanks
Chris
Chris Schmitt, P.E.
Principal
17304 Preston Road, Suite 1340
Dallas, Texas 75252
214.461.9867 Main
214.988.9913 Direct
903.421.1897 Mobile
214.461.9864 Fax
cschmitt@tnpinc.com <mailto:cschmitt@tnpinc.com>
-----Original Message-----
From: Keith Marvin [mailto:KMarvin@coppelltx.gov]
Sent: Sunday, October 19, 2014 6:02 PM
To: Chris Schmitt
Subject: Re: Response requested -- Re: Question - New Left turn lanes
at Sandy Lake and Denton Tap
Thanks Chris.
Keith Marvin
City of Coppell
> On Oct 19, 2014, at 5:59 PM, "Chris Schmitt" <cschmitt@tnpinc.com>
wrote:
>
> Keith,
>
> I was able to visit the site late last week to observe the turning
movements at the intersection. I also asked Robert Jenkins to review the
layout. He forward me the attached exhibits and notes below. We
attempted to connect on Friday to discuss but I was out of the office on
a school field trip with my youngest.
>
> Chris,
>
> The two attachments show the situation with a WB-50 and a WB-62
situation assuming that a truck and a passenger vehicle are turning side
by side in each direction. Traditionally this is the situation and not
two trucks side by side in both directions. We showed the two truck
scenarios because we did not know the City’s criteria. Note that with
the WB-62, the truck uses part of the outside lane on Denton Tap for his
departure. These drawings suggest to me that the dual lefts are ok,
especially since a truck is not normally involved, cars should not have
a problem.
>
> However, if needed, I will be glad to observe in the field.
>
> Robert
>
> I’ll call you tomorrow morning to discuss this as well as provide
update on other items for Sandy Lake.
>
> Thanks
>
> Chris
>
>
> [Description: Description: M:\_Logos\TNP
Logos\2012_ReBranding\_MASTER TNP Logo_Color.jpg]
>
> Chris Schmitt, P.E.
> Principal
> 17304 Preston Road, Suite 1340
> Dallas, Texas 75252
> 214.461.9867 Main
> 903.421.1897 Mobile
> 214.461.9864 Fax
> cschmitt@tnpinc.com<mailto:cschmitt@tnpinc.com>
>
>
>
>
> From: Keith Marvin [mailto:KMarvin@coppelltx.gov]
> Sent: Sunday, October 19, 2014 5:32 PM
> To: Jo Ann H. Hill
> Cc: Mario Canizares; George Marshall; Kenneth Griffin; Chris Schmitt
> Subject: Re: Response requsted -- Re: Question - New Left turn lanes
at Sandy Lake and Denton Tap
>
> Mrs. Hill,
>
> As the project manager for the Sandy Lake Road project, it was my
responsibility to respond to your inquiry concerning the new turn lanes
at Sandy Lake and Denton Tap. I apologize for not getting back to you
in a timely manner.
>
> Several of us have observed the movement of traffic through this
intersection, and we agree with your assessment that it presents an
uncomfortable situation for drivers. We have discussed this situation
with both the city Traffic Engineer, and the design engineer for the
project. We are looking at options ranging from physical modification
of the intersection to operational changes of the signal to minimize the
likelihood of conflicts between these two left turning movements.
>
> We hope to have a decision in the near term. Thank you for bringing
this concern to our attention.
>
> Keith Marvin
> City of Coppell
>
> On Oct 19, 2014, at 4:26 PM, "Kenneth Griffin"
<KGriffin@coppelltx.gov<mailto:KGriffin@coppelltx.gov>> wrote:
> Yes, I received your email and forwarded it to my engineer for that
project. He and I met with my Traffic Engineer last week to discuss the
issue. We are considering several options to address your concern.
Someone will be in contact with you next week.
>
> Ken Griffin
>
>
> On Oct 19, 2014, at 3:20 PM, Jo Ann H. Hill
<joannhh@usa.net<mailto:joannhh@usa.net>> wrote:
> Hi Ken, please let me know if you received my email sent last week,
and considerations for a resolution.
> Best regards,
> Jo Ann
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Jo Ann H. Hill
> (H) 972-393-1137
> (C) 214-236-8260
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ------ Original Message ------
> Received: 10:41 PM CDT, 10/12/2014
> From: "Jo Ann H. Hill" <joannhh@usa.net<mailto:joannhh@usa.net>>
> To: <kgriffin@coppelltx.gov<mailto:kgriffin@coppelltx.gov>>
> Subject: Question - New Left turn lanes at Sandy Lake and Denton Tap
>
> Hi Ken, I realize that the road construction is new and may not be
totally complete yet; however, I wanted to voice a concern that the new
two left turn lanes (coming from the West) turning onto Denton Tap can
possibly present a danger of car collisions with drivers making a left
turn (coming from the East) because the turns are made at the same time.
>
> Many drivers have also been hesitant in making the turns because
visually, it doesn't appear safe.
>
> Please advise if you require further details on this observation.
> Best regards,
> Jo Ann
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Jo Ann H. Hill
> (H) 972-393-1137
> (C) 214-236-8260
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
>
>
> <image001.jpg>
> <WB-62.pdf>
> <WB-50.pdf>