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City of Santa Ana | First Street Multimodal Boulevard Study
<br />RFP NO. 25-029 | B. Services Provided
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<br />2.1.2 Travel Patterns and Volumes
<br />HDR will use a combination of Replica data and ground count data to
<br />develop the existing traffic volumes and patterns. Replica is a big data
<br />source that can be used to understand travel patterns using origin and
<br />destination information, traffic volumes by mode, and other information.
<br />Since Replica uses data from IP addresses and sums the data over a multi-
<br />year period, it can also be a source of data patterns and trends. Existing
<br />conditions for traffic, pedestrian, bicycle, heavy vehicle, and transit volumes
<br />will be collected. Volumes will be collected for all intersections (signalized
<br />and unsignalized) and daily traffic volumes, including speed and vehicle
<br />classification, will be collected for up to 15 segments.
<br />2.1.3 Evaluation of Safety
<br />HDR will use SWITRS/TIMS to develop an understanding of reported
<br />crashes. Our preliminary evaluation of the available data, summarized in
<br />Figure 1 below, revealed 11 fatalities and 13 severe injury collisions out of
<br />381 crashes over the past 7 years, including a very high crash density at
<br />Bristol Street. We understand the City received HSIP grant funding (Cycle
<br />10 and Cycle 12) to address some of the these critical areas. We will review
<br />the projects that received funding, and if not currently constructed, will
<br />integrate those improvements into our overall concept development.
<br />SWITRS/TIMS data is not capable of providing near miss information and
<br />only includes crashes that were reported. In many cases, accident reports
<br />are not filed for fender benders and non-injury crashes. Therefore, this
<br />data only paints a portion of the conditions along the corridor. Near miss
<br />information is critical to providing insight into safety issues that exist but
<br />are not reported.
<br />HDR proposes to use LiDAR detection technology to collect near miss data
<br />at major intersections and crash hot spots. We will install these detectors
<br />at key locations and collect one week of data along the corridor. This data
<br />will provide information on near misses that can then be compared with
<br />video obtained through the City’s Traffic Management Center (TMC) to
<br />determine where potential problems exist before we propose alternative
<br />design improvements.
<br />2.1.4 Understanding Challenges through Field Investigation
<br />While the LiDAR survey will collect the location of signs and other features,
<br />it cannot identify the type of sign or post mounting. Therefore, a field
<br />investigation will be conducted to clearly identify wayfinding, speed limit,
<br />and other signs along the corridor.
<br />The field investigation will identify and document bus stop amenities
<br />including shelters, benches, lighting, trash cans, bicycle storage, and other
<br />features. We will also review boarding and alighting information and
<br />on-time bus performance from data to be provided by OCTA. HDR will
<br />confirm intersection geometrics, roadway striping, and signal operations.
<br />We will request as-built plans and traffic signal timing plans from the
<br />City, and will work closely to understand current traffic signal technology,
<br />communications, and ITS elements, which will be used to evaluate needs
<br />regarding integrating transit signal priority (TSP) or other technology into
<br />the design concepts.
<br />Finally, the team will document general observations relative to pavement
<br />condition, sidewalk condition/ADA compliance, sidewalk widths, trees
<br />and shade structures, lighting, and general activity along the corridor. To
<br />illustrate community use of the street, the team will note activity of people
<br />traveling along, to, and from the corridor, as well as any prolonged activity,
<br />such as street vending or gatherings. Potential mobility challenges that will
<br />be documented include grade changes at the rail crossing/I-5 interchange
<br />and skewed intersection crossings.
<br />HDR will confirm any planned improvements along First Street and/or
<br />any connecting streets with the City, OCTA, and Caltrans. These projects
<br />will be documented during this existing conditions phase and taken into
<br />consideration during concept development.
<br />CRASH DENSITY LEVEL
<br />Figure 1: Crashes at Study Area Intersections
<br />Very low
<br />Low
<br />Moderate
<br />High
<br />Very High
<br />2.2 Existing Multimodal Facilities Map
<br />All data collected will be recorded in GIS. Existing sidewalks, bicycle
<br />facilities, transit stops, and roadway conditions (lanes, volumes, speeds and
<br />crashes) will be input into a corridor database. This data will be overlaid
<br />on an existing land use map and will include consideration of informal land
<br />uses and economic drivers. HDR’s Community Analytics team conducted an
<br />initial analysis of the corridor and surrounding project area to gain a better
<br />understanding of the community, as documented in the infographic on the
<br />following page.
<br />2.3 Existing Corridor Model
<br />HDR recommends building a VISSIM model for the corridor to demonstrate
<br />the existing six-lane operation and how the proposed four-lane condition
<br />along the corridor will operate. The first pass will be agnostic as to how
<br />the two outside lanes are re-purposed. The intent is to demonstrate
<br />potential congestion points and potential solutions to addressing traffic and
<br />transit flow within the modified roadway capacity. To properly prepare a
<br />microsimulation model, four key steps are needed:
<br />1. Develop the Base Model
<br />Before we begin a VISSIM simulation, we will utilize City-provided Synchro
<br />files to develop an existing peak hour conditions model that is calibrated
<br />for current traffic operations. This will allow us to calibrate both the peak
<br />hour Synchro models and the baseline VISSIM model for proper operation.
<br />HDR will use the combination of the Synchro model and baseline VISSIM
<br />model to test the various multimodal alternatives that are recommended.
<br />Using Synchro to model current traffic operations conditions is more time
<br />efficient and provides the necessary database for testing the traffic signal
<br />timing modifications that may be required to accommodate TSP, leading
<br />pedestrian intervals, or bike track signal operations.
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