A00805-613295.pdf

Massachusetts Department Of Transportation Highway Division Proposal No. 613295-133722

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DOCUMENT A00805

NON-COMPLIANT ROADSIDE SAFETY

HARDWARE APPROVAL

Massachusetts Department Of Transportation Highway Division

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THIS PAGE INTENTIONALLY LEEFT BLANK

MassDOT Highway Division Request and Documentation for the use of

Non-Standard or Non-Compliant Roadside Safety Hardware

Basic Information

Location: Greenfield

Description: Log Plain Road West over G&W Railroad Deck Replacement

Date of Request: 7/28/2025

Project Information

Project File Number: 613295

Designer: Jacobs Engineering Group, Inc.

MassDOT Project Manager: Muazzez G. Reardon

Current Design Stage: 100%

Advertising Date: 12/20/2025

Facility Information

Asset Owner: Massachusetts Department of Transportation

NHS Roadway (Y/N): N

AADT: 879 (2024)

Design Year AADT: 971 (2044)

Target Speed: 25 MPH

Design Speed: 25 MPH

Measured Speed: 40 MPH (85th Percentile)

Posted Speed Limit: 25 MPH

Designer Certification

Date

MassDOT Approval

Chief Engineer Date

7/28/2025

9/3/25

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Project Description

The proposed bridge preservation project for Bridge No. G-12-022 is to remove and replace the existing exposed 7.25" deck and concrete railing systems with an 8" deck with 3" of superpave overlay and install S3-MTL4 railing systems on safety curb on both sides of the bridge and 5'-6" sidewalk on the north side of the bridge only. The existing buried deck ends will be removed and replaced with buried deck ends utilizing integral abutment stems. Precast highway guardrail transitions will be located at all four corners of the bridge to transition the bridge rail to highway guardrail. The steel girders shall remain and be cleaned and painted. The bearings on pier 2 will be replaced with elastomeric bearings.

Roadway work associated with the bridge work includes installing MASH-compliant guardrail on the approaches to the bridge, pavement reconstruction to accommodate profile raise, pavement mill & overlay, and minor intersection modifications at Newell Pond Road/Log Plain Road at

Severance Street. The proposed 30-foot-wide roadway includes two 15 ft wide travel lanes to match the existing conditions. The proposed project will include a new 5.5-foot-wide sidewalk on the north side of the bridge. There are no proposed sidewalks outside of the project limits.

The total project length including the bridge is 300 feet.

Required Safety Hardware

In accordance with the MassDOT Project Development and Design Guide (PDDG) Chapter 5

Section 5.6.2.4, roadside barrier is required due to the 2:1 embankment slope, proposed bridge railing, and the presence of trees/utility poles. The following guardrail items are required for the approaches to the bridge:

- Transition to Bridge Rail (Back of Sidewalk) (MassDOT Construction Standard 628.24.1)

- Transition to Bridge Rail (Face of Curb) (MassDOT Construction Standard 628.24.2)

- Guardrail, TL-2 (MassDOT Construction Standard 620.12.1)

- Guardrail Tangent End Treatment (MassDOT Construction Standard 627.0.1)

- Guardrail Trailing Anchorage (MassDOT Construction Standard 627.1.1)

Description of Problem(s)

The close proximity of the intersection of Log Plain Road with Severance Street/Log Plain Road

(as it continues north) and Bridge No. G-12-022 over the G&W railroad does not provide sufficient space to install standard bridge rail transitions with guardrail end treatments and/or trailing anchorages in the northeast and southeast quadrants of the bridge. Modifications to the standard bridge rail transitions and treatments are proposed.

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Proposed Solution(s)

The proposed solution, as shown in Appendix A, proposes to attach a modified Transition to

Bridge Rail from the precast concrete highway guard transition on both sides of the roadway to the east of the bridge. In the northeast quadrant, the 12’-6” Thrie Beam Panel (Nested) and 6’-

3” Thrie Beam Transition Panel shall be installed parallel to the roadway at back of sidewalk in accordance with MassDOT Construction Standard 628.24.1. The following 12’-6” W-Beam

Panel shall be installed at a 9:1 taper away from the back of sidewalk with 3’-1 ½” post spacing and terminated with a rounded end unit prior to the side street intersection. With this layout, the rounded end unit will be located approximately 6’-8” feet from the edge of travel lane of approaching traffic. There shall be a 6” vertical granite curb and sidewalk in between the edge of travel lane and the proposed guardrail.

In the southeast quadrant, the 12’-6” Thrie Beam Panel (Nested) and 6’-3” Thrie Beam

Transition Panel shall be installed parallel to the roadway at face of curb in accordance with

MassDOT Construction Standard 628.24.2. The following 12’-6” W-Beam Panel shall be installed at a 9:1 taper away from the back of sidewalk with 3’-1 ½” post spacing and terminated with a rounded end unit prior to the side street intersection. With this layout, the rounded end unit will be located 16’-10” feet from the edge of travel lane of approaching traffic.

Basis of Proposed Design

The proposed design was developed from guidance in Chapter 5 of the AASHTO Roadside Design

Guide, Chapter 5 of the MassDOT PDDG, and. Relevant information from design references includes:

• The maximum suggested flare rate for guardrail along a road with a 30 mph is 7:1 per

MassDOT PDDG Figure 5-31.

• The Recommend Clear Zone for this roadway is 10-12 feet per MassDOT PDDG Exhibit 5-

19 (Design Speed of 30 mph, ADT = 879 vehicles per day).

• MassDOT Construction Standards 628.24.1 and 628.24.2 are used for the proposed design and are slightly modified in accordance with the PDDG.

Alternate Designs Reviewed

Five design alternatives were considered and reviewed. Below are descriptions of these alternatives and the sketch for the preferred alternative can be viewed in Appendix A.

Alternative 1 (Preferred)

This alternative is described above under Proposed Solution(s).

Alternative 2

This alternative proposes a guardrail transition from the northeast precast highway guardrail transition. The beginning 27’-6” of this piece will be tangential, with the remaining 6’-3” section requiring curved guardrail (radius of 17 feet). This connects to curved TL-3 guardrail, which then

A00805 - 5 transitions to a tangent end treatment with an impact head terminal. To the east of the intersection, a 60-foot length of guardrail has been proposed on the north side of the roadway.

The intent of this run of guardrail is to deflect errant vehicles from potentially entering the wooded area/train tracks. Due to the low traffic volumes on the roadway, this alternative was not selected.

Alternative 3

This alternative proposes an impact attenuator at the northeast corner of the bridge. To connect the impact attenuator to the bridge rail, the standard precast highway guard transition shown in

MassDOT Construction Standard 628.24.1 would need to be modified. In addition, the impact attenuator requires a concrete pad underneath the system. This alternative would increase the project costs while providing similar safety measures as the preferred alternative.

Alternative 4

This alternative proposes a relocation of the intersection with Newell Pond Road and Severance

Street to provide space for standard highway guardrail treatments in accordance with current design standards. Due to limited right-of-way and surrounding residential land, this alternative is not feasible.

Alternative 5

This alternative proposes to provide no guardrail protection along the northeastern side of the roadway. Due to hazards posed by the blunt end of the bridge rail and the roadside slopes down to the railroad tracks, this alternative was not selected.

Recommendation

In consideration of the roadside safety design practices in the AASHTO Roadside Design Guide, the MassDOT PDDG, and the context of the roadway and project area, including the low traffic volume, posted speed of 25 mph, urban local roadway classification of the road, and site constraints, the recommendation is to install bridge transitions and guardrail as described in the

Proposed Solution(s) section of this request.

The proposed solution represents a constructible guardrail system which offers improved roadside safety in comparison to the existing guardrails and does not require extensive site disturbance nor reconstruction/realignment of the side streets.

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APPENDIX A

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(PUBLIC~VARIABLE W

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Propsal No. 613295-CCCCCC

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