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21st Century Operations Using 21st Century Technologies

US 50 Integrated Corridor Management – Sacramento Region

4. US 50 Corridor Challenges and Issues

The deployment of the US 50 ICM project, will address many of the issues and challenges that are currently present on the US 50 Corridor. Recent studies have shown that the US 50 corridor experiences frequent operational deficiencies stemming from non-recurrent traffic collision incidents. The analysis included number of collisions per mile, total vehicle miles traveled and vehicle hours of delay. Additional factors were considered, such as multimodal opportunities (transit, light rail, bicycle facilities, park and ride/transit stops, and the maturity of transit facilities), adjoining and parallel arterial networks, as well and as the participating agencies and their capabilities to implement ICM without major systems reconstruction.

The incident or collision analysis was completed for 2014 using TASAS (Traffic Accident, Surveillance and Analysis System) data and for 2016 using the California Highway Patrol Computer Aided Dispatch (CHPCAD) incident data. Per analysis, the US 50 corridor was ranked as having the second or third highest incident rate in the Region depending on the year analyzed. Although State Route 51 and Interstate 80 had a greater number of incidents per mile, when evaluated considering the variables detailed above, the study participants elected to move forward with US 50 which also had a significant number of incidents per mile (see Table 2 and Figure 2).

Table 2: TASAS and CHP CAD Incident Data
Freeway Corridor Freeway Miles 2014 TASAS Collisions Collisions per mile 2016 CHP CAD Incidents Incidents per mile
I-5 127 1,116 9 6,136 48
US 50 109 1,838 17 8,922 82
SR 51 9 639 71 3,351 372
SR 65 30 218 7 62 2
SR 70 81 224 3 768 9
I-80 132 2,123 16 12,866 97
SR 99 117 1,539 13 5,756 49
SR 113 38 87 2 205 5
SR 160 48 89 2 267 6

 

Figure 2: 2014 and 2016 Incidents by Route. 2014 Collisions: I-5 - 1116, US 50 1838, SR 51 - 639, I-80 - 2123, SR 99 - 1539. 2016 All Incidents: I-5 - 6136, US 50 8922, SR 51 - 3351, I-80 - 12866, SR 99 - 5756

Figure 2: 2014 and 2016 Incidents by Route

 

Table 3: District 3 Caltrans Performance Management System - VMT and VHD
Freeway Corridor Detection Coverage Miles 2016 Vehicle Miles Traveled (VMT) VMT per mile 2016 Vehicle Hours Delay (VHD) VHD per mile
I-5 46 1,693,751,000 29,946,000 1,814,000 39,400
US 50 47 2,321,711,000 43,503,000 2,399,000 51,000
SR 51 9 478,643,000 52,212,000 2,051,000 227,900
SR 65 13 303,522,000 22,829,000 270,000 20,800
SR 70 10 187,067,000 15,404,000 245,000 24,500
I-80 105 3,475,781,000 30,316,000 2,911,000 27,700
SR 99 48 1,778,030,000 37,122,000 2,170,000 45,700
SR 113 15 329,753,000 13,531,000 191,000 12,700
SR 160 4 64,844,000 14,295,000 209,000 59,700
Figure 3: 2016 VMT and VHD by Route.  Vehicle miles traveled for 2016: I-5 - 1,750,000, US 50 - 2,450,000, SR 51 - 500,000, SR 65 - 250,000, SR 70 - 200,000, I-80 - 3,500,000, SR 99 - 1,7500,000, SR 113 - 300,000, SR 160 - 100,000. Vehicle Hourss Delay: I-5 - 1,800,000, US 50 - 2,475,000, SR 51 - 2,000,000, SR 65 - 250,000, SR 70 - 250,000, I-80 - 2,900,000, SR 99 - 2,225,000, SR 113 - 200,000, SR 160 - 200,000

Figure 3: 2016 VMT and VHD by Route

The primary purpose of the US 50 ICM project is to improve the safety and travel time reliability on the US 50 Corridor, enhance transportation system management and integration, reduce the growth of daily vehicle hours of delay, improve incident response, maintain ITS element health, reduce primary and secondary collisions, more effectively coordinate multimodal traveler information improve roadside safety, and reduce GHGs.

After determining to move forward with the US 50 corridor, Caltrans and its partners examined the three proposed segments by the same factors for comparison purposes and to assure the participants that no one segment dominated the statistics (see Table 4). It can be observed that the higher hours of delay in the downtown urban core segment (Segment 1) align with the highest incident rate segment.

Segments 1 and 2 pass through three different jurisdictions and bordered on two additional agencies at the boundaries. The incident rates, VMT and VHD, are significant for ICM testing purposes and the ability to incorporate multiple transit agencies make these two segments a good initial test bed choice.

Table 4 US 50 ICM Corridor Attributes
Attributes Segment 1 Segment 2 Segment 3
Description Sacramento Downtown Urban Core Suburban Sacramento County Suburban El Dorado County
Limits Enterprise Blvd (West Sac) to Howe Ave (Sac County) Howe Ave (Sac. County) to Folsom Blvd (Folsom) Folsom Blvd (Folsom) to Cameron Park Dr (El Dorado County)
Length 10 Miles 14 Miles 13 Miles
Local Arterial Jurisdictions West Sacramento, Sacramento Sacramento, Rancho Cordova, Folsom, Sacramento County El Dorado County, Folsom
Transit Agencies Yolo Bus, SacRT(bus and light rail) SacRT, CordoVan, El Dorado Transit, Folsom Stage Lines El Dorado Transit, Folsom Stage Lines
Multimodal hubs Howe/Power Inn Watt, Bradshaw, Mather Field, Sunrise, Hazel, Iron Point Latrobe Road (Post Street)
Existing (2016) Vehicle Miles Traveled (VMT) 559,703,000 806,968,000 641,253,000
Existing (2016) Delay (vehicle hours) 1,370,000 619,000 288,000
Existing (2014) TASAS Collisions 674 543 190
Existing (2016) CHP CAD Incidents 3,869 2,981 1,212

Implementing ICM strategies in both Segments 1 and 2 will improve performance of a Transportation Management System (TMS) without increasing capacity on US 50, leading to better Transportation System Management and Operations (TSMO).

This US 50 ICM project provides the opportunity for Caltrans and its partners to address multiple Concepts for ICM Implementation that were identified in the US 50 ICM Implementation Plan.

Ranked Concepts for ICM Implementation:

  1. Address non-recurrent congestion
  2. Provide corridor-specific traveler information system
  3. Optimize multimodal operations
  4. Manage goods movement and truck traffic
  5. Address recurrent congestion

The concept of ICM will allow managers across agency boundaries to coordinate their actions, assess available capacity, and address a surge in demand at any one facility (e.g., as a result of an incident). When implemented in conjunction with Traveler Information (TI), the public can plan their points of exit from and entrance to the highway and ease impact on the local arterials and residential streets. By monitoring the performance of the corridor, additional capacity can be allocated in the direction of demand and reduce travel delay in a coordinated fashion, as illustrated in Figure 5.

Figure 4: Trypical Public Response to an Incident - Accident on US50.  Arrows denote several alternate routes chosen around stretch of highway where accident occurred.  A lot of alternate routes denoting chaos.

Figure 4: Typical Public Response to an Incident

Figure 5: ICM Approach to Redistributed Demand - Green arrows denote an orderly single alternative route taken by commuters after accident on US50.

Figure 5: ICM Approach to Redistributed Demand

This coordinated approach to the demand will reduce the amount of "cut through traffic" in neighborhoods and on local streets, by enhancing capacity along the arterial network where applicable. As capacity of the arterial network is reached, Traveler Information can then be updated to inform public of the expected poor condition of the arterial network (and likely better conditions on the freeway by comparison) and discourage traffic from departing the highway system.

Traveler Information should also be used to inform motorists of other modes and/or route options available before beginning their trips or if already en route, before completing those trips. Providing real-time and accurate information on the status of the transit system and other available modes as part of the response plan allows the public to make informed decisions when choosing their mode, time of travel, and route to avoid traffic congestion. Caltrans and its partners worked together to take the following actions for the first phase of deployment for the US 50 ICM Project:

  • Automatically detect congestion events
  • Real-time (multimodal) decision support
  • Network traffic prediction
  • Real-time response strategy assessment
  • Dynamic rerouting
  • Freeway adaptive ramp metering
  • Signal coordination with freeway ramp metering
  • Regional arterial management
  • En route traveler information
  • Pre-trip traveler information

US 50 Integrated Corridor Management Project 11 Additional strategies and systems for the US 50 integration are:

  • Freeway system improvements
    • Corridor adaptive ramp metering
    • Advanced central signal control
    • Freeway vehicle detection and performance monitoring (VDS, Bluetooth/Wi–Fi, other sensors)
    • Traveler Information and Routing
  • Arterial system improvements
    • Intersection control upgrades
    • Arterial vehicle detection and performance monitoring (VDS, Bluetooth/Wi-Fi, other sensors)
    • Trailblazer signing
  • Other systems (transit, parking, active transportation, trucks)
  • Integration System (decision support system, data hub, interfaces, etc.)
  • Traveler information system
  • Pre–planned and pre–approved response plans to various corridor conditions scenarios

Current congestion management approaches on freeways and arterials are not able to make full use of all network capacity as they have little to no visibility of conditions on adjacent facilities. Information on incidents, events, and changes in demand on one facility that may impact conditions on another are not communicated, even though this information may be critical in managing a response.

This multi–jurisdictional consortium realized that the pre–existing gaps in coordination, visibility and communications have prevented the full potential of the existing ITS system. Higher degrees of institutional integration and ITS build–out are needed in order to take full advantage of the transportation infrastructure capacity along the US 50 corridor.

Some of these have already been implemented or funded to be implemented along the corridor; however, the infrastructure will need additional investments before a complete proof of concept can be validated. Measurement of the performance of the transportation systems under before and after conditions will be required to determine the actual return on investment and gains in system performance. Data collection as required for the analysis should become a priority and investments should keep this data collection need in mind as choices are made on system investments.

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