Josh Mello Chief Transportation Official FUTURE CONDITIONS & LESSONS FROM ONGOING TRAFFIC CIRCULATION STUDY SEPTEMBER 16, 2017
FUTURE CONDITIONS & LESSONS FROM ONGOING TRAFFIC ... · Traffic Operational uses a meso-simulation model \⠀ 匀礀渀挀栀爀漀 尩 . Final layouts can be t\sted with VISSIM \⠀
FUTURE CONDITIONS & LESSONS FROM ONGOING TRAFFIC CIRCULATION STUDY
SEPTEMBER 16, 2017
Presenter
Presentation Notes
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Traffic Circulation Study
Overview of Study being performed Assessing ‘what if’ scenarios related to alternatives at Palo Alto Ave, Churchill Ave, Meadow Dr, Charleston Rd
• Do nothing • Close completely • Bikes/Pedestrians separated crossing only • Full grade separation • Mix and match alternatives
Presenter
Presentation Notes
Tested a range from all closed except Charleston to all grade separated except Churchill with Oregon widened . Results are intuitive .
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Traffic Circulation Study – At Grade Crossings
Methodology of Study • 2017 traffic counts • Volume growth based on regional projections (MTC/VTA) • “Best practices” assignments for growth and traffic diversion
Two model approach: • Palo Alto Travel Demand Model (regional => projected volumes) • Traffic Operational (localized => assess impacts such as delays, queuing,
levels of service) • Several roadway modification scenarios tested
Presenter
Presentation Notes
This is a planning level study so far . Traffic Operational uses a meso-simulation model ( Synchro ) . Final layouts can be tested with VISSIM ( micro-simulation ) but not worth doing at this level & too detailed . VISSIM is a deign aid & for detailed MOE Analyses . This is normal approach for this stage of the project – any further layouts can easily be tested , model all set up .
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Traffic Circulation Study
General notes • Actual train times vary day to day. Modeling assumes uniform
(averages)
• Peak hours based on typical times of year (schools active)
• Actual travel delay > increased gate closures due to stopping and starting
• Gate crossing pre-emption requirements preclude ability to synchronize lights on Alma Street
Presenter
Presentation Notes
Close together closures tend to cause more delay ( non-linear relationship ) Need VISSIM model to test these . Variables for delay & queues are timing & frequency of closures ; traffic demand ( volume & profile ) ; crossing physical features ; pedestrian demand ;
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Gate Closures – Average vs. Actual
Peak period average is 6 trains per hour today
Actual
Average
Actual - not evenly spaced – varies ‘daily’
Presenter
Presentation Notes
There is a difference in real life to what is scheduled to happen as trains don’t run exactly to schedule – the point here is that the operations of trains could be scaled up by the 6 to 12 to 20 factors – that the message the slide is trying to get across. Closely spaced closures tend to cause more delay ( but not necessarily so depends on other variables too ) as traffic operations do not have time to recover between closures . These slides are meant to convey the scale of change in the future when the increased services come on line Caltrain Hazards study survey (2013), identified one hour when 10 gate closures occurred – but the average for the 8 hour ( AM + PM ) peak periods overall is close to 6. Going from 6 to 12 & then to 20 is the information Caltrain & HSR quote & we used before in outreach #1 . The actual was taken from the Caltrain survey .
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Effects of: Caltrain Modifications
Current Caltrain operations (peak period average today) • 6 trains per hour (total both directions) - Can be up to 10 per hour • Effective Gate Closure time: 45 seconds every 10 minutes
(7.5% of peak hours)
(Actual train spacing varies daily)
Recent data shows gates were closed roughly 1 hour each day
Presenter
Presentation Notes
This slide conveys the amount of time when the capacity is restricted by closures . The point here is that the operations of trains could be scaled up by the 6 to 12 to 20 factors – that the message the slide is trying to get across. These ( & following ) slides are meant to convey the scale of change in the future when the increased services come on line
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Effects of: Caltrain Modifications
Anticipated changes in Caltrain operations (projected 2020) • 12 trains per hour (total both directions)
• Gate closure time: 45 seconds every 5 minutes (average) (15% of peak hours = 9 minutes in peak hour)
(Actual train spacing varies daily)
Presenter
Presentation Notes
4 hours for both AM & PM in line with the modeled time periods and shape of demand profiles . Reality means it could be 10-20 for an hour . So these are not peak of peaks .
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Effects of: Caltrain Modifications Impact of changes to Caltrain operations (2020) • 10% capacity reduction of roadways vs. 2017
• Vehicle delays - increase by 11% for AM, 18% for PM
• Some traffic will likely re-route to existing grade separated crossings
Presenter
Presentation Notes
Drivers do not sit in queues endlessly and will divert if it is quicker . More likely for longer distance traffic to divert as can re-align earlier in journey .
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Gate Closure Delays (Peak Hours)
(Actual train spacing varies daily) Caltrain Only
Presenter
Presentation Notes
Again , intended to convey the scale of change .
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Effects of: Caltrain & High-Speed Rail Mods
Anticipated operational changes (2025 – with HSR) • 20 trains per hour (total both directions)
• Gate closure time: 45 seconds every 3 minutes (up to 25% of the time in peak hours)
*Without HSR: Caltrain might add trains to fill new capacity
Presenter
Presentation Notes
Reality could reduce time between closures causing more delay .
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Effects of: Caltrain & High-Speed Rail Mods Impacts in 2025 with Caltrain and HSR operating: • ~20% capacity reduction of roadways vs. 2017
• Vehicle delays: 60%+ increase for AM, 100%+ for PM
Some traffic will likely re-route to existing grade separated crossings
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Presentation Notes
Charleston highest for delay escalation .
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Gate Closure Delays (Peak Hours)
Caltrain + HSR
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Presentation Notes
Meant to show escalating changes in the potential for delay to road traffic .
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Queue Lengths (2030 PM Peak: 20 trains/hour)
Palo Alto Ave Churchill Ave
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Presentation Notes
Frequency of closure generated traffic queues will occur over 3 times as often in peak periods The analyses is at 2030 because that is the model forecast year – but also allows for HSR delayed opening & for everything ( driver behavior ) to settle down .
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Queue Lengths (2030 PM Peak: 20 trains/hour)
Meadow Dr Charleston Rd
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Presentation Notes
Frequency of closure generated traffic queues will occur over 3 times as often in peak periods in 2030 as compared to now . This represents a “weighted average “ condition . These are the 95 percentile queues ( as defined by Synchro- not average ) – so a 1 in 20 chance they could be longer . Only the traffic crossing the rail tracks included . AM lighter Reassignment effects included . .
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AM & PM Delays in Seconds for 2017, 2020, 2030
Average delay per vehicle crossing Caltrain tracks
Caltrain operating at planned leve HSR operating as planned No changes to existing crossings
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Presentation Notes
Delay and queuing analysis considers latest City data. I.e. already approved changes to the intersections, such as at Churchill where the traffic light will move back, prohibiting right hand turns. Charleston & PA in pm worst . Big step up in delays from 2020 to 2030 . Shows power function profile of Volume/delay curve .
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Results from On-going Circulation Study No improvements to roads; No Caltrain or HSR changes • Traffic volumes crossing the tracks forecast to increase ~15% by 2030
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Presentation Notes
This was just to build up the picture & make sense of what came after. If nothing is done, traffic volume across tracks will increase by ~15% by 2030. There will probably be a very small amounts traffic diversion ( around 3 % max on any one route ) but it really starts to happen when the increased services reduce the capacity of the crossings markedly – this is a theoretical scenario because Caltrain increase will occur .
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Results from On-going Circulation Study No road improvements; Caltrain and HSR operating as planned • Similar traffic volume growth (15%) - some traffic will divert to existing
grade separated routes
Presenter
Presentation Notes
Diversion to existing grade separations causes between 3% & 8 % increase to City ones . San Antonio goes up to a 10 % increase in the PM peak period . Tend to be longer distance trips .
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Results from On-going Circulation Study Some crossing closures; Caltrain and HSR in operation • Total crossing traffic volume would remain similar to now and growth
would divert out of the City
• Bikes/Peds impacted - active transportation modes could decline
Presenter
Presentation Notes
This takes into account the already grade separated roads (University, Oregon, Embarcadero) Need Bike /Ped grade separated close by if closed . Tested with 3 at grades closed but Charleston grade separated . So not a full closure test .
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Results from On-going Circulation Study Multiple grade separations; Caltrain and HSR in operation • Crossing traffic volumes could increase by over 20% – would vary by
location of grade separation.
• Grade separating one location only attracts 5-10% more traffic to that location in comparison to grade separating all locations.
Presenter
Presentation Notes
Bullet 1 assumes all at-grades are separated except Churchill & Oregon is widened . 20% represents the baseline plus 5% additional traffic to 3 grade separations. All increase from 2017 quote. We have tested 6 scenarios with up to 3 at-grade crossings as in the Rail Committee report Need to make it clear that doing 4 grade seps, does not mean traffic increases 80%. Increases would likely stabilize around the 20% - 25% mark The second bullet point may only apply to Charleston – no tests of just Palo Alto ; Churchill or Meadow as a single grade separated crossing have been done .
20 Josh Mello Chief Transportation Official
FUTURE CONDITIONS & LESSONS FROM ONGOING TRAFFIC CIRCULATION STUDY
