This page outlines the procedures for assessing various safety and operational impacts related to vehicle, bicycle, and pedestrian activities as well as potential queueing impacts from freeway off-ramps. Here are the key steps:
Assessment of Vehicle, Bicycle, and Pedestrian Safety Impacts:
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Review Access Points: Evaluate all project access points, internal circulation, and parking access from both operational and safety perspectives. Consider factors such as turning radii, driveway queuing, and line of sight for turns into and out of project driveways.
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Consider Conflicts: Pay special attention to project driveways that would intersect with pedestrian or bicycle facilities (e.g., bike lanes or bike paths). Assess the potential for conflicts between vehicles and pedestrians or bicycles, and evaluate the severity of consequences that could result from such conflicts.
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Pedestrian and Bicycle Count Data: In areas with moderate to high levels of pedestrian or bicycle activity, collect pedestrian or bicycle count data to inform the assessment.
Assessment of Freeway Off-Ramp Queueing Impacts:
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Queuing Study: For projects expected to add 25 or more trips to any off-ramp during the morning or afternoon peak hour, conduct a queuing study for the "Future with Project" conditions in the proposed project build-out year. Utilize Synchro analysis software or similar tools for this purpose.
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Evaluate Storage Length: Assess the adequacy of existing and future storage lengths by using the 95th percentile queue obtained from the Synchro results worksheet. Consider the full length of each lane from the stop line to the gore point. If there's an Auxiliary Lane, add 50% of its length to the ramp storage area.
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Impact Thresholds: Determine the impact based on queue length:
- If the project is expected to cause or add to a queue extending onto the freeway mainline by less than two car lengths, it's considered a less-than-significant safety impact.
- If the queue already extends onto the mainline, and the project increases it by less than two car lengths, it's also considered a less-than-significant safety impact.
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Speed Differential Analysis: If the project adds two or more car lengths to the ramp backup that extends to the freeway mainline, assess safety issues. This includes analyzing the speed differential between the off-ramp queue and the mainline of the freeway during the corresponding peak hour. A speed differential of 30 mph or more indicates a potential safety issue.
Review of Access Plans for Related Projects:
Examine access plans for related projects that have access points proposed along the same block(s) as the proposed project. Determine the combined impact and the specific contribution of the proposed project to assess potential cumulative impacts.
These steps help ensure that project access and traffic operations are assessed comprehensively from a safety and operational perspective, taking into consideration the potential impact on various modes of transportation and the safety of freeway off-ramps.
Please contact us if you need help preparing a transportation assessment report for a development project in the City of Los Angeles LADOT.