Connecting Palo Alto Projects
Caltrain Technical Review
January 23, 2024 www.cityofpaloalto.org
1 Purpose
2 Purpose
• Rail Committee’s review of comments to provide guidance to staff on specific elements.
• Direct staff to proceed coordination with Caltrain Staff or their Consultants and/or City’s project consultant for material changes to alternatives
Background
3 • Select Preferred Alternative to Proceed with
Preliminary Engineering and Environmental PhaseGoal
• Federal Railroad Administration (FRA) Grant Funding
Agreement in place by July 1, 2024.Objective
• Rail Committee to provide guidance to on
implementing design changes sufficient to support
the goal.
Guidance
Background
4 CAP &
XCAP
• Alternatives developed, reviewed and updated (2018 - July 2020) • Community Outreach & Community Feedback (August – October 2020) • Deliberation and Recommendation to City Council (November 2020 - March 2021) City
Council
• Council Review and Discussion
• Meadow Drive – Charleston (Narrowed Alternatives) - August 2021 • Churchill Avenue (Preferred Alternative & Backup Selection) - November 2021 Rail
Committee
• Reviewed and Refined underpass alternatives (June 2023) • Reviewed and updated Council Adopted criteria
• Conducted Review of Preliminary Geotechnical
Caltrain /JPB
Review
• Service Agreement with Caltrain (June 2023)
• Technical Review and Comments to City November 2023
Overview of Caltrain Capital Project Management Process 5 Major Elements
6 Vertical Alignment
Vertical Clearance
Bridge Structure Elevation (Viaduct Only)
Railroad Grade Profile
Pedestrian and Bicycle Path Clearance
Horizontal Alignment
Roadway Encroachment into Caltrain ROW
Pedestrian & Bicycle Facilities Encroachment into Caltrain ROW Railroad Encroachment into City’s ROW
Retaining Wall offset/clearance from structures and roadways Maintenance Access requirement along the railroad tracks Clearance for MSE Wall construction during construction and maximize use of ROW
Four Track Segment
Four Track segments and Roadway encroachment into Caltrain ROW Four Tracking Alignment
Roadway Design
Road Profile, Sag Curves, Grades etc.
Offset from Barriers
Acceleration/Deceleration Lanes, Lane drops,
weaving distance, etc.
Roundabout Design
Curved bridges
Construction Technology
Shoofly vs Box Jacking
Culverts
Reconstructing and extending culverts
Cost Estimates
Preliminary Cost Estimates
Cumulative Concerns
Compounded impacts from above comments
Vertical Alignment (Correction)
7 1. Vertical Dimensions (Roadway Vertical Clearance required across Caltrain ROW )
Vertical Clearance for vehicular traffic under the Railroad (Increase from 15.5’ to
16.5’)
Likely affects
length of
roadway profile
Meadow Charleston - Hybrid
Profile View
Min vertical clearance is
16’-6” across ROW
Caltrain
ROW
Caltrain
ROW
Min vertical
clearance is 16’-6”
across ROW
Caltrain
ROW Caltrain
ROW
Meadow Drive Underpass
Vertical Alignment (Correction)
8 2. Vertical Dimensions (Top of Rail to Top of Roadway – Viaduct Alternative only) Vertical Clearance for vehicular traffic under the Railroad (Increase from 20.5’ to 24.0’) Provide 24’
vertical distance
Provide 24’
vertical distance
Likely affects
length of
roadway profile
Meadow Charleston - Viaduct Alternative
Summary of Comments - Churchill Avenue
9 Churchill Closure with Mitigations - Option 1
• New active transportation facilities should be placed outside of Caltrain ROW.
If not, they are subject to JPB Board approval
* No Changes for Churchill Avenue Closure with Mitigations Option 2 Summary of Comments - Churchill Avenue – Closure Option 1 10 Plan View
Section A-A
Section B-B
4-Track Influence Area
Transition between 2-Track and 4-TrackNew active
transportation
facilities should be
placed outside of
Caltrain ROW. If not,
subject to JPB Board
approval.
Extend tunnel to
extent of Caltrain
ROW
Relocate stairs
outside of
Caltrain ROW. If
not, subject to
JPB Board
approval.
Summary of Comments - Churchill Avenue – Closure Option 2 11 Alma St
Mariposa
Ave
Plan View
Section A-A
Section B-B
4-Track
Influence Area
Transition between 2-Track
and 4-Track
Show lane
width and
shoulder
dimension
s
No Major/Significant
Concerns
Summary of Comments - Churchill Avenue
12 Churchill - Partial Underpass
• New active transportation facilities should be placed outside of Caltrain ROW.
If not, they are subject to JPB Board approval.
• Adjust retaining walls outside of Caltrain ROW.
• Provide 16’6” vertical clearance requirement for the extent of the Caltrain ROW—will require reprofiling of roadway
• Bridge width to provide access for Caltrain maintenance and emergency vehicles.
• Roadway design to meet Caltrans HDM/AASHTO ‘Greenbook’/AASHTO ‘Highway Safety Manual’
Profile View
Extend bridge width to
Caltrain ROW to provide
access to Caltrain
maintenance and emergency
vehicles
4-Track Influence Area
Transition between
2-Track and 4-Track
New active transportation
facilities should be placed
outside of Caltrain ROW.
If not, subject to JPB
Board approval.
Summary of Comments - Churchill Avenue – Partial Underpass 13 Roadway & Walls to
be outside of
Caltrain ROW
Provide 16’-6”
vertical clearance
Will affect length
roadway profile,
ROW, Driveways,
intersection, etc.
Other elements:
• Merging taper/median
design
• Offset from barriers
• Lane width etc.
• Curved bridges
Summary of Comments – Meadow Drive & Charleston Road
14 Meadow Charleston - Underpass
• Provide 16’6” vertical clearance requirement for the extent of the Caltrain ROW—will require reprofiling of roadway.
• Provide bridge width to provide access for Caltrain maintenance and emergency vehicles.
• Adjust retaining walls outside of Caltrain ROW to accommodate 4-track and 4- track transitions, provide sufficient space (10’ min) for maintenance vehicle access, and maximize utility of Caltrain ROW.
• Roadway design to meet Caltrans HDM/AASHTO ‘Greenbook’/AASHTO ‘Highway Safety Manual’
Summary of Comments – Meadow Dr - Underpass
15 Plan View (Meadow Drive)
4-Track Influence Area Transition between 2-Track and 4-Track Adjust wall/foundation design
and location to be outside of
the Caltrain ROW. Additional
width is not needed for turning
lane sight distance.
Min vertical clearance is
16’-6” across ROW,
which will impact ROW,
Driveways, road profile.
Min vertical
clearance is 10’
across ROW
Caltrain
ROW
Caltrain
ROW
Caltrain
ROW
Caltrain
ROW
Increase bridge width to
provide access road for
maintenance and emergency
vehicles
Steep grade limits
options for design
flexibility
Summary of Comments –Charleston Rd - Underpass
16 Plan View (Meadow Drive)
4-Track Influence Area Transition between 2-Track and 4-Track Min vertical clearance is 16’-
6” across ROW,which will
impact ROW,Driveways, road
profile.
Min vertical
clearance is 10’
across ROW
Caltrain
ROW Caltrain
ROW
Caltrain
ROW
Caltrain
ROW
Increase bridge width to
provide access road for
maintenance and emergency
vehicles
Steep grade limits
options for design
flexibility
Summary of Comments – Meadow Drive & Charleston Road
17 Meadow Charleston - Hybrid
• Provide 16’6” vertical clearance requirement for the extent of the Caltrain ROW.
• Adjust retaining walls to accommodate 4-track and 4-track transitions. • Provide sufficient space (10’ min) for maintenance vehicle access and maximize utility of Caltrain ROW.
• Provide sufficient space (10’ min) clearance from the walls to the roadway or structures
• Construction of permanent MSE walls to be at 20’ from center of shoofly track—constructability clearance from OCS and active railroad.
Summary of Comments – Meadow Dr & Charleston Rd - Hybrid 18 Plan View
Profile
Fill retaining walls to accommodate 4-
track and transition between 2-track
and 4-track
1% grade is the current maximum
without variance. 1% to 2% grade
requires review and approval by the
Director of Engineering
Min vertical clearance requirement
is 16’-6” across ROW
Provide additional width on the
bridge to accommodate access
road for maintenance and
emergency vehicles
4-Track Influence Area Transition between 2-Track and 4-Track Design speed is 110
mph for passenger
rail
Transition segment should
be tangent as special
trackwork should stay
outside of vertical curves
Summary of Comments – Meadow Dr - Hybrid
19 Profile View
Plan View
Typical Section
Min vertical clearance is
16’-6” across ROW
Caltrain
ROW
Caltrain
ROW
10’ to maximize
utility of ROW
10’ min for maintenance
access between face of
retaining walls/ barriers and
adjacent
obstruction/roadway
Confirm proximity of OCS
and centerline of tracks
Width not
sufficient for
maintenance
vehicle access
Provide additional
width on the bridge to
accommodate a
maintenance and
emergency vehicle
access
Summary of Comments – Charleston Rd - Hybrid
20 Min 16’6”
clearance across
Caltrain ROW
Plan View
Profile View
Min vertical
clearance is 16’-6”
across ROW
10’ to maximize
utility of ROW
Caltrain
ROW
Caltrain
ROW
10’ min for maintenance access
between face of retaining walls/
barriers and adjacent
obstruction/roadway
Confirm proximity of OCS
and centerline of tracks
Provide additional
width to the bridge
for maintenance and
emergency vehicle
access
Typical Section
Summary of Comments – Meadow Drive & Charleston Road
21 Meadow Charleston - Viaduct
• Provide 16’6” vertical clearance requirement for the extent of the Caltrain ROW— will require reprofiling of roadway and/or Caltrain tracks. • The vertical dimension from the top of the roadway to the top of the rail should be 24’ instead of 20’ to accommodate 5-foot bridge depth and 2’-6” Rail. • Provide bridge width to provide access for Caltrain maintenance and emergency vehicles.
• Adjust retaining walls to accommodate 4-track and 4-track transitions. • Provide sufficient space (10’ min) for maintenance vehicle access and maximize utility of Caltrain ROW.
• Construction of permanent MSE walls to be at 20’ from center of shoofly track— constructability clearance from OCS and active railroad. • Roadway design to meet Caltrans HDM/AASHTO ‘Greenbook’/AASHTO ‘Highway Safety Manual’
Summary of Comments – Meadow Dr & Charleston Rd - Viaduct 22 4-Track Influence Area Transition between 2-Track and 4-Track Fill retaining walls to accommodate 4- track and transition between 2-track
and 4-track
1% grade is the current maximum
without variance. 1% to 2% grade
requires review and approval by the
Director of Engineering
Increase distance roadway to top of
rail to 24’ to accommodate 16’-6”
roadway clearance
Design speed is 110
mph for passenger
rail
Transition segment should be tangent as
special trackwork should stay outside of
vertical curves
Plan View
Profile
Summary of Comments – Meadow Dr & Charleston Rd - Viaduct 23 Place the permanent track
alignment to enable
maintenance and maximize
utility of ROW
16’-6” min
from roadway
to soffit
10’ min for maintenance
access between face of
retaining walls/ barriers and
adjacent
obstruction/roadway
Confirm proximity of OCS
and centerline of tracks
Extend OCS
foundation to
connect with
bridge pier
The plans show
part of the viaduct
constructed
outside Caltrain
ROW
Typical End Section Typical Section
Next Steps
24 Next Steps
The goal is to provide sufficient information for Rail Committee to evaluate alternatives and make recommendation to the City Council. Therefore, Staff is seeking
• Rail Committee’s review of comments to provide guidance to staff on specific elements.
• Direct staff to proceed coordination with Caltrain Staff or their Consultants and/or City’s project consultant for material changes to alternatives
25