From: Jennifer Cline
Sent: Fri Nov 06 09:38:56 2015
To: Randall Stark
Cc: Chris Link; Daphne Marcyan; Hash, Kenneth F.
Subject: RE: Molalla Avenue Urban Renewal Project
Importance: Normal
Hi,
I only have a couple questions. See below
Jennifer Cline, P.E. | Public Works Director
Licensed in OR, WA
117 N Molalla Ave. | PO Box 248 * |Molalla, OR 97038
O: 503.759.0218 | F: 503.829.3676
From: Randall Stark [mailto:Randall.Stark@msa-ep.com]
Sent: Friday, November 06, 2015 8:34 AM
To: Marlene.T.NICHOLS@odot.state.or.us
Cc: Jennifer Cline <jcline@cityofmolalla.com>; Chris Link <Chris.Link@msa-ep.com>; Daphne Marcyan <Daphne.Marcyan@msa-ep.com>; Hash, Kenneth F. <HashK@hdjdg.com>
Subject: Re: Molalla Avenue Urban Renewal Project
Good morning Marlene,
We have reviewed the questions regarding the Molalla Avenue / OR211 (Main Street) intersection posed by ODOT Engineer Lawerence Krettler after his review of the project plans. Following are our responses:
1) Don’t use curb and gutter on state highway.
Response: Standard curb can be used instead of curb and gutter at these locations. Will new curb and gutter end at the radius returns on Molalla Ave?
2) They need to provide more detail to determine if design exception is needed. Example – what is the counter slope?
Response: The approximate existing counter slopes are as follows,
NW corner: single ramp, diagonal direction = 5.7%
NE corner: double ramp, E-W direction = 2.1%, N-S direction = 4.1%
SE corner: double ramp, N-S direction = 4.7%, E-W direction = 3.9%
SW corner: single ramp, diagonal direction = 8.9%
Sawcuts in the street to reconstruct the curb returns & ramps will typically be 3’ offset from the gutter line. The replaced AC pavement and new curb ramps will be designed per ODOT/PROWAG requirements such that the counter slope is no greater than 5% and ramp/counter slope grade differential will be less than 11% (whichever is less). Updated plans will be provided showing the specific grades and slopes at these four quadrants.
3) The state uses curb radius in multiples of 5’. Is there a reason for the odd radiuses.
Response: The new curb returns are designed to closely match the existing curb return radius. We are matching the existing odd curb return radii (and not enlarging the radius) due to space limitations caused by existing surrounding infrastructure, such as buildings and utility/signal poles, storm inlets, as well as limited right-of-way.
4) Is there a reason for going to the minimum width of ADA ramp on the single ramps.
Response: The curb ramps are designed showing the minimum 5-foot width per the ODOT standard drawings. While the intersection corners are constricted, it is possible to increase ramp widths to 6 feet, which will be pursued. Updated plans to follow.
5) The north west corner is going from a double ramp to a single ramp. Why?
Response: The existing ramp at the NW corner is a single ramp, and is proposed to be re-constructed as a single ramp. The 90% design plans provided to ODOT show the existing double ramp at the NE corner going to a single ramp. This has since been re-designed to remain a double ramp. Updated plans to follow.
6) No inlets going on the upstream side of ADA Ramps. Why?
Response (see attached sketch for details):
NW corner – This corner is a high point and drains away in both the west and north directions. An upstream inlet is not necessary.
NE corner – It is City staff’s experience that drainage flows past this ramp without ponding and creating issues. Will the new roadway surface create a ponding point at the ramps in the future? OR are we able to match in as the existing surface is today?
SE corner – This corner is a low point. The 90% design plans provided to ODOT show only 2 of the 3 inlets at this corner. There is another existing inlet immediately upstream of the north-south ramp. Updated plans to follow.
SW corner – The project can install a new inlet on Molalla Avenue inlet immediately upstream of the ramp.
We will provide updated intersection plans in the near future. In the meantime please feel free to contact us if you would like to discuss the intersection design. Thank you for your assistance with this project.
Sincerely,
Randy Stark, P.E. | Civil Engineer
Licensed in WA, OR
T: 360.448.4230 | F: 360.448.4239 | Randall.Stark@msa-ep.com
400 E Mill Plain Boulevard, Suite 203 | Vancouver, Washington 98660-3492 | www.msa-ep.com
Murray, Smith & Associates, Inc. | Your Public Works Partner
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_____________________________________________
From: KRETTLER Lawerence A
Sent: Tuesday, October 13, 2015 10:23 AM
To: NICHOLS Marlene T
Cc: HILL Merle E
Subject: RE: Molalla Avenue Urban Renewal Project
1) Don’t use curb and gutter on state highway
2) They need to provide more detail to determine if design exception is needed. Example – what is the counter slope?
3) The state uses curb radius in multiples of 5’. Is there a reason for the odd radiuses.
4) Is there a reason for going to the minimum width of ADA ramp on the single ramps.
5) The north west corner is going from a double ramp to a single ramp. Why?
6) No inlets going on the upstream side of ADA Ramps. Why?
Lawerence A Krettler
Senior Roadway Designer
ODOT Region 1
123 NW Flanders
Portland OR 97209
Phone 503.731.8488
Fax 503.731.8531