October 14, 2003        

SUBJECT: Mathilda Avenue/Caltrain Bridge Rehabilitation Project – Project Alternatives Study

REPORT IN BRIEF

This project involves widening and modification of the Mathilda Avenue bridge at Evelyn Avenue and the Caltrain tracks to address deficiencies identified by Caltrans.  Caltrans inspects bridges statewide on a bi-annual basis and identifies structural and functional deficiencies.  The current bridge design does not meet bridge column clearance standards, deceleration lane design standards (“gore point”), shoulder width standards, ADA accessibility, and bridge railing standards.  These deficiencies create potential hazards to the public, and present a potential liability issue for the City.

City staff have successfully secured federal funds (80%/20% local match) for removing the deficiencies and improving traffic circulation on the bridge. Conceptual designs have been explored and a feasible alternative identified.  As part of the proposed bridge improvement, staff recognized the added benefit of reconfiguring the off ramp to Evelyn Avenue to allow full access to Evelyn from southbound Mathilda Avenue.  This improvement can service the anticipated increase in traffic from southbound Mathilda Avenue to downtown Sunnyvale. 

A consultant team has been retained to prepare design and environmental documentation.  At the time of award of contract, the City Council directed staff to explore an additional design concept suggested by a citizen for a “roundabout” alternative.  Staff and the consultant team have prepared a project alternatives study that develops preliminary information on two variations of the proposed Roundabout Alternative.  Staff has held a community meeting and reviewed the study with the Bicycle and Pedestrian Advisory Committee.

Based on study findings of significant cost, operations and environmental issues, as well as neighborhood opposition, staff recommends that the City Council discontinue further consideration of the Roundabout Alternative as part of the project design and environmental process.  

EXISTING POLICY 

Land Use and Transportation Element C3, Attain a transportation system that is effective, safe, pleasant and convenient.

Land Use and Transportation Element C3.4, Maintain roadways and traffic control devices in good operating condition.

Land Use and Transportation Element C3.1.4, Study and implement physical and operational improvements to optimize roadway and intersection capacities.

Land Use and Transportation Element N1.5, Support a roadway system that protects internal residential areas from City-wide and regional traffic.

Land Use and Transportation Element C3.5, Support a variety of transportation modes. 

BACKGROUND

The Department of Public Works is pursuing a capital project for the rehabilitation of the Mathilda Avenue overpass structure at Evelyn Avenue.  The structure is a primary arterial street that spans over two Caltrain tracks and Evelyn Avenue.  There are also two connector ramps to and from Evelyn Avenue, which also span over the Caltrain tracks.  The existing bridge was built in 1965 and underwent seismic retrofits in 1981 and in 1993.  According to the latest Caltrans bridge inspection report done in April 2000, the bridge was evaluated with a Sufficiency Rating of 79.7, and was found to be “functionally obsolete”.  The bridge is also on the Federal Highway Administration’s Eligible Bridge List (EBL). 

The City Council considered informational reports on the project proposal and staff’s intent to pursue bridge rehabilitation funding at its December 19, 2000 and April 30, 2002 meetings.  Council has also received a project update at an October 16, 2001 study session, an April 30, 2002 information report, and an August 13, 2002 Council meeting.  A City Council community meeting was held October 16, 2002. The Downtown Stakeholders Advisory Committee considered the project during its deliberations over the Downtown Urban Design Study.  The Stakeholders Committee unanimously endorsed the need for the project and recommends its construction. The Bicycle and Pedestrian Advisory Committee considered the project at its April, 2001, July, 2002, August, 2002 and September 2003 meetings. 

The City has secured funding for preliminary engineering through the Federally funded Highway Bridge Rehabilitation and Reconstruction (HBRR) program, and a funding commitment is in place for construction funding.  At its July 15, 2003 meeting, the City Council awarded a contract for design and environmental services to a project team led by Mark Thomas & Company.  At that meeting, the Council responded to a citizen request that a project alternative be explored that would facilitate access to downtown Sunnyvale by exiting traffic from southbound Mathilda Avenue to westbound Evelyn Avenue, and return that traffic eastbound towards downtown via a roundabout on Evelyn.

Additional conceptual design work or detailed investigation of project alternatives was not specifically included in the consultant’s work scope.  Staff met with the consultant team and negotiated the preparation of an alternatives study that would develop a concept design and general information on issues and benefits of the proposed alternative within the existing design scope.  This information can be used in the environmental analysis for the project.  This report is now complete.  Staff has presented the report findings to the Bicycle and Pedestrian Advisory Committee at its September 18, 2003 meeting, and at a community meeting on October 29 at the Murphy Park building. 

DISCUSSION

The roundabout study looked at differences between the primary project proposal, a “Loop Ramp”, and the roundabout proposal.  The Loop Ramp Alternative would exit southbound Mathilda traffic via a loop ramp and full access intersection in the vicinity of Charles Street and Evelyn Avenue. The Roundabout Alternative would exit traffic on a reconstructed southbound Mathilda to eastbound Evelyn ramp, divert downtown traffic west on Evelyn to a roundabout at Evelyn/Pastoria, and return it east to downtown.  Other than the configuration of ramps for exiting southbound Mathilda traffic, all other bridge rehabilitation elements would remain the same. 

Two Roundabout Alternatives were studied, one assuming four travel lanes on Evelyn Avenue, and one assuming two travel lanes (and a reduced footprint for a roundabout intersection). Illustrations of the three concepts are presented as Attachments “A” (Loop Ramp), “B” (4 lane roundabout), and “C” (2 lane roundabout)).

The Study found that while both the Loop Ramp and Roundabout alternatives improve traffic access, the Roundabout Alternatives are considerably more expensive and have potentially more environmental issues.

Both the Loop Ramp and Roundabout Alternatives would improve traffic conditions at the Mathilda bridge by eliminating the existing substandard ramp from southbound Mathilda Avenue to westbound Evelyn Avenue.  Both provide a quicker route for southbound Mathilda traffic to reach downtown Sunnyvale than existing conditions.  However, there may be a perception that the west bound access to Evelyn to the Roundabout and back to east bound Evelyn to access the downtown takes longer and prompt traffic to continue to the Mathilda/Washington intersection for downtown access.

Roundabout Alternative – Construction Issues

Both the Loop Ramp and Roundabout Alternatives require total reconstruction of the ramp structure from southbound Mathilda Avenue to Evelyn Avenue, in order to address geometric requirements for diverging off ramps and design speed requirements.  The Roundabout Alternative locates the point of divergence for the ramp approximately 160 feet further north on Mathilda Avenue than the loop ramp alternative.  This requires bridging of the Caltrain tracks using a cast in place structure versus a pre-cast method which can be used with the loop ramp alternative.  This increases the cost of the project considerably.  Additional higher costs are for greater paving, drainage, and roadway work on Evelyn Avenue. 

Overall costs for the two roundabout alternatives were estimated at $ 21.9 million and $ 19 million for the two- and one-lane alternatives respectively, versus $ 14.4 million for the loop ramp alternative.

The Roundabout Alternative ramp structure also significantly increases construction encroachment on the Caltrain tracks.  This greatly affects constructability, as special work around rules must be in effect for construction around trains.  A primary impact of these rules is a lengthening of the time of construction, which affects cost.  Special training, inspection, plan approval and operations also are effects.

Right of way impacts associated with the Roundabout ramp are greater.  Due to the greater angle of divergence, an additional estimated 6,200 s.f. of right of way would be required from the Applied Signal Technology facility just west of Mathilda Avenue.  The roundabout intersections themselves have right of way impacts ranging from minor to major.  Two alternatives were studied, one assuming four lanes on Evelyn and one assuming two lanes.  Roundabout geometry was based on Federal Highway Administration guidance.  The four lane alternative would require the taking of two to three homes on the corner of Pastoria and Evelyn.  This is a major impact.

The City has a pending bicycle lane project to consider reduction of travel lanes on Evelyn Avenue from four lanes to two.  Therefore, a second alternative utilized geometry assuming two lanes on Evelyn.  This would require smaller right of way acquisition from residential properties at the corners of Pastoria, as well as some right of way from Caltrain.  With respect to the HBRR funding program, this program does not fund work more than 250 feet from the location of the structure to be rehabilitated, so roundabout costs would need to be borne by the City or some other funding source.  Staff estimates the costs of roundabout construction in association with the ramp construction to be $883,000 to as much as $ 3.7 million, including right of way acquisition. 

Roundabout Alternatives – Operations Issues

The Roundabout Alternatives would largely mimic existing circulation, with the exception of creating an “allowed/encouraged U-turn” on Evelyn Avenue to facilitate downtown access.  Drivers desiring to reach downtown Sunnyvale from southbound Mathilda Avenue would first travel west on Evelyn Avenue, then reverse direction at the roundabout and return east to downtown. 

Much traffic headed to downtown from southbound Mathilda Avenue would continue to do so via the current optimal route, a left-turn at the Mathilda/Washington intersection.  This left turn movement is projected to operate at or above capacity during certain peak times of day.  Potential diversion to Evelyn Avenue with the Roundabout Alternative is estimated in the 20 to 30% range, due to the counter-intuitive nature of exiting away from the destination.  This level of diversion may not be sufficient to address the capacity issue at the Mathilda/Washington left turn.  If this diversion increases to the 50% range then some relief would be provided at Mathilda/Washington, but a single lane roundabout would probably not operate efficiently with the greater traffic load. 

The Roundabout Alternatives carry the potential to increase non-neighborhood traffic on residential streets south of the new off-ramp from Mathilda Avenue to Evelyn Avenue and would not permit travel in the eastbound direction (i.e., toward downtown) unless motorists choose to first travel westbound to the roundabout.  This will increase traffic and traffic noise on Evelyn Avenue adjacent to the residential streets of Charles, Waverly, Florence, and Pastoria.  Upon reaching the roundabout, motorists could either reverse direction on Evelyn Avenue or access downtown through the neighborhood via Pastoria and Washington Avenues. While the degree of potential diversion to the neighborhood cannot be accurately predicted, if 30% of estimated traffic using the roundabout diverted to Pastoria/Washington Avenue it would mean essentially a 100% increase in local street use. 

Existing non-neighborhood traffic has been identified as a problem by residents of Charles Street.  Non-neighborhood traffic uses Charles Street to travel from Mathilda Avenue to Evelyn Avenue.  The Loop Ramp alternative addresses this issue by potentially creating a cul de sac of Charles Street to accommodate the terminus of the loop ramp.  This option is supported by Charles Street residents. Existing non-neighborhood traffic has been flagged as the primary issue facing this neighborhood, primarily traffic accessing downtown from Washington to Evelyn via Charles Street.  The neighborhood believes the loop ramp project with a Charles Street cul de sac will solve their traffic issue.  The Roundabout Alternatives would perpetuate the existing traffic pattern and may increase local street volumes due to the added traffic into the area from the Mathilda Avenue off ramp heading toward down town.

The Roundabout Alternative would preserve the 115 space parking lot at Charles and Evelyn Avenues.  This lot would likely be fully taken by the Loop Ramp Alternative.

Roundabout Alternatives – Environmental Issues

The project environmental consultant made a sketch level analysis of potential environmental issues with the Roundabout Alternative.  Tree removal, traffic divergence, neighborhood traffic noise, and neighborhood air quality were found to be of greater concern with the Roundabout Alternative.  Because of a greater construction footprint, there is also the potential for cultural resources and storm water pollution impacts.  The Loop Ramp Alternative also better addresses City General Plan policy on intrusion of non-neighborhood traffic into residential neighborhoods, which can be construed as a positive impact.  The Roundabout Alternative may present negative impacts with respect to this policy.  The environmental consultant concludes that the level of environmental review would potentially increase to the Environmental Impact Report/Statement (EIR/S) level should the Roundabout Alternative be carried forward, whereas the current project proposal is anticipated to require a Mitigated Negative Declaration, and has been determined to require only a federal Initial Study/Environmental Assessment.  Increased environmental review will add substantial cost to the project design phase.  

The location required for the Roundabout Alternative ramp structures impacts trees more significantly than the Loop Ramp Alternative. A double row of pine and redwood trees located just west of Mathilda is affected by all project alternatives.  The Roundabout Alternative ramps must diverge at a greater angle than the Loop Ramp Alternative, however.  The Roundabout Alternative removes 23 more trees than the Loop Ramp Alternative.

The Loop Ramp alternative is anticipated to have potential noise and aesthetic impacts to residents in proximity to the ramp on Charles Street and Mathilda Avenue.  These impacts would be lessened by the Roundabout Alternative.  Noise and aesthetic impacts can be lessened under either scenario to less than significant levels with soundwalls and construction techniques and materials.  

Public Outreach

Per Council direction, staff has conducted outreach to present the study findings to the Bicycle and Pedestrian Advisory Committee at their September 18, 2003 meeting (Attachment “D”).  Staff also conducted a community meeting on September 29, 2003, at the Murphy Park Building.  Approximately 20 people attended the meeting.  A summary of input from the meeting is attached (Attachment  “E”).

Community Issues

Several issues raised by the public and BPAC stood out in the public outreach process.  The first had to do with the design of the roundabout off ramp.  Concern was raised that the design used specifically biased against a Roundabout Alternative by utilizing a more expensive design than is necessary.  The specific contention is that a lower design speed could be used on the curve radius of the Roundabout Alternative ramp, such as that used for the loop ramp.  This change could bring the cost of the alternatives closer together. 

Staff and the consultant investigated whether use of a lower design speed on the curve of the Roundabout Alternative ramp would affect the point of divergence or otherwise obviate the need for cast in place construction, which is the more expensive component of the Roundabout ramp.  The Roundabout ramps use a 25 MPH design speed, while the Loop Ramp uses a 20 MPH design speed.  The 25 MPH design speed selected for the Roundabout ramp was a function of the available distance for deceleration, while the 20 MPH speed for the Loop was a function of the available space for the loop ramp.  Substituting a 20 MPH ramp design speed for the Roundabout ramps causes the length of the diverging lane to increase to provide increased deceleration. This does not eliminate the requirement for cast in place bridging, and would lengthen the deceleration lane so as to encroach into the Fire Station # 1 and the Mathilda/California intersection at the north end of the bridge.  This would constitute a significant cost and environmental issue.  Attachment “F” illustrates the length of the deceleration segments for the Roundabout Ramp versus the Loop ramp.  The 25 MPH design speed is appropriate to minimize impacts and lower construction costs. 

Members of the BPAC expressed concern that improvements for bicyclists are not assured with the project.  The BPAC is on record as supporting the provision of full width shoulders from California Avenue to Washington Avenue.  The project is not yet at a stage where these designs have been considered or fully prepared, but staff believes that these features can be achieved and staff is committed to their pursuit.  Unknowns include Caltrans approval of what may be considered an extra work item and the availability of right of way, but conceptual designs prepared by staff and reviewed by Caltrans have included shoulder improvements.  Staff believes that the provision of shoulders where none exist greatly improves bicyclist safety.

Finally, issues were raised having to do with the cost estimates for the roundabout intersections and the potential savings to the City of substituting a Pastoria/Evelyn roundabout project for the bridge rehabilitation. A member of the public contended that roundabout costs were inflated when compared to estimates made by staff for roundabout construction at the Bernardo/Knickerbocker intersection.  The Bernardo/Knickerbocker estimates, prepared as part of a 2000 Study Issue, assumed no right of way acquisition, no drainage work, no lighting and no pavement work.  The same assumptions cannot be applied as easiliy to the Pastoria/Evelyn single lane roundabout.  Right of way would be required to construct a roundabout at Pastoria/Evelyn, and significant exceptions to good design practice would be required.  The Bernardo/Knickerbocker location is a wide, symmetrical intersection that is better suited to retrofitting for a roundabout, while Pastoria/Evelyn is not. 

The Bernardo/Knickerbocker intersection has two wide approaches which could be made to accommodate minimum design requirements, whereas the Pastoria approach to the Evelyn/Pastoria intersection is too narrow to meet FHWA minimum requirements.  Right of way would also be required from Caltrain to provide a workable radius to the roundabout.  If additional pavement requirements were designed with conforms rather than total pavement replacement, then pavement costs might be lower for the initial construction.  However this would result in a poor pavement structure and would eventually require total replacement in any case.  Drainage patterns in theory could be maintained in their current locations, although this might create drainage flows in the traveled way, and uneven and uncomfortable rides for vehicles negotiating the intersection.  Deletion of lighting is a possibility, although the bridge consultant determined that existing lighting would be inadequate for the roundabout intersection whereby it was adequate for Bernardo/Knickerbocker.   

The citizen’s and the BPAC’s comments about roundabout costs are directed at the notion that a roundabout by itself, without reconstruction of the ramp, could be a lower cost downtown access improvement. The Bicycle and Pedestrian Advisory Committee voted to support abandonment of the bridge rehabilitation project.  The BPAC supports maintaining the structure as is and constructing a single lane roundabout on Evelyn Avenue.  It is true that a roundabout by itself would result in a lower overall cost to the City.  A large component of the cost estimates for roundabout construction at Pastoria/Evelyn are roadway costs—pavement, drainage and utilities.  When a roundabout is integrated with reconstruction of the ramp, then a significant portion of Evelyn Avenue is assumed to be reconstructed.  These reconstruction costs would be slightly lower if a roundabout only were constructed.  A cursory staff estimate is that a roundabout only at Pastoria and Evelyn would cost in the range of $500,000 - $800,000.  This would indeed be less of a cost than is currently projected for the City’s share of the bridge rehabilitation project.  However, there are significant additional benefits associated with the bridge rehabilitation including safety, ADA, traffic operations, neighborhood improvement and bicycle travel.  Staff believes that the City’s investment in an overall bridge rehabilitation project, coupled with the significant amount of federal funds leveraged, provides a singular opportunity to provide a wide range of beneficial improvements to the area.

It should be noted that at the July 16, 2002 meeting of the BPAC, the BPAC voted to support the Mathilda Avenue Bridge Improvement project with the following assumptions:

1. Evelyn Avenue becomes converted to two travel lanes, one two way left turn lane, and bike lanes in both directions to improve access to the Caltrain station (the City has an adopted capital project and a federal air quality grant to complete this project).
2. That a pedestrian walk be installed from California Street to Washington Avenue that meets ADA standards the entire distance.
3. That there be no free right turn lane on Charles Street.
4. That standard width shoulders be provided from California Street to Washington Avenue on Mathilda Avenue. 

Staff will continue to work with the BPAC to address issues with bicycle/vehicle merging and overall pedestrian circulation in the area.  Staff believes that all design issues initially raised in the BPAC’s statement of support can be satisfactorily addressed in the project design.  Staff believes that declining to move forward with the rehabilitation will place the City in a position of significant liability.  

Citizens in attendance at the September 29 community meeting were largely opposed to the Roundabout Alternative for a myriad of reasons, including increased/continuing traffic intrusion in the neighborhood, traffic noise, air quality, right of way impacts, and project cost.  One citizen spoke in support of abandonment of the bridge rehabilitation project and construction of a single lane roundabout on Evelyn as a means to improve downtown access.  Charles Street residents are strongly in favor of the Loop Ramp Alternative, and are supportive of a project in general.

One email was received from the neighborhood representative of the Charles Street neighborhood group indicating support for the Loop Ramp Alternative with a Charles Street cul-de-sac, with a second choice of no project. 

Next Steps

The current project schedule calls for the design and environmental consultants to begin work immediately.  Environmental clearance is anticipated to occur by April, 2005, with design completion anticipated in February, 2006.  It is anticipated that Caltrans’ consideration of a high cost project application will take 2-3 months in winter 2006.  Assuming approval of the high cost project application, the current schedule calls for construction beginning in summer, 2006 and lasting approximately 18 months.

 The project requires a number of reviews and approvals by the California Department of Transportation.  For this reason, and dependent upon other unanticipated events that may occur over the course of this major project, this schedule must be considered optimal and subject to change.

Staff Recommendation

Staff believes that the negative cost, operational and environmental issues associated with the Roundabout Alternatives prompt the elimination of these alternatives from any further consideration.  Input from the broader community was not supportive of the Roundabout Alternative.  The BPAC did not support the Roundabout Alternatives as presented. Based on the findings of the project alternatives study and community input, staff recommends that the City Council discontinue further consideration of the Roundabout Alternative as part of the project design and environmental process.  Staff does not recommend abandonment of the bridge rehabilitation project.

FISCAL IMPACT

There is no fiscal impact associated with the staff recommendation.  The currently estimated project cost is $ 14.44 million. The HBRR program will fund up to 80% of a project’s cost, although Caltrans has indicated that this project could potentially be capped at a $ 10 million maximum contribution.  Assuming that City funds would pay for the local share, the City share would be as much as $ 4.4 million, or approximately 30% of the project cost. Currently, the City budget includes a $ 3,499,300 City local match.  Current City expenditures on design and environmental services are covered by the HBRR program and budgeted City funds.

Further consideration of the Roundabout Alternatives will result in a negative fiscal impact to the City due to required changes in the scope of the current design and environmental services contract.  The estimated cost to carry additional alternatives forward through the preliminary design and environmental process is estimated to be $ 350,000.  It is uncertain whether a portion of this cost would be reimbursable through the HBRR Program.          

Alternatives

1.      Based on the findings of the project alternatives study and community input, discontinue further consideration of Roundabout Alternatives as part of the project design and environmental process.

2.      Direct staff to negotiate with the design consultant and Caltrans to conduct further preliminary design and environmental analysis of a Roundabout Alternative through the completion of the project environmental review, and return to Council with a revised scope of services, funding agreement, and Budget Modification upon successful conclusion of negotiations.

3.      Abandon the bridge rehabilitation project and direct staff to pursue an Evelyn Avenue roundabout as a means to improve access to downtown Sunnyvale from southbound Mathilda Avenue. 

4.      Abandon the bridge rehabilitation project and discontinue further consideration of a Roundabout as a separate project.

RECOMMENDATION

Staff recommends Alternative 1.

Prepared by:

Jack Witthaus
Transportation and Traffic Manager 
 

Reviewed by:

Marvin A. Rose
Director, Public Works 

Approved by:

Robert S. LaSala
City Manager 

Attachments:

Attachment “A”:  Loop Ramp Alternative

Attachment “B”:  4 Lane Roundabout Alternative

Attachment “C”:  2 Lane Roundabout Alternative

Attachment “D”:  September 18, 2003 BPAC Minutes

Attachment “E”:  Community Meeting Summary

Attachment “F”:  Roundabout, Loop Ramp Configuration Overlay