Every weekday in Los Angeles, more than 400,000 people take a car trip on Wilshire Boulevard, one of the most iconic streets in America. And each day, about 10% of those trips — more than 40,000 people — drive on Wilshire as it bisects MacArthur Park in Westlake.
But that may not be the case for long.
In early July, the City of Los Angeles announced a planning process to explore closing the road to vehicular traffic as it makes its way through the park. The goal of the $2.5-million planning process, primarily funded through a federal grant, is to understand the pros and cons of the closure.
On one hand, the City has a stated goal to create more pedestrian-friendly park space in the area, and make this space more accessible to the primarily low-income, majority immigrant local population. On the other hand, the City needs to understand the potential drawbacks on the transportation network if the road was to be closed — would it cause too much traffic? Who would be most impacted? Would it wreak havoc on commutes?
Traditionally, expensive traffic impact analyses to study those potential downsides might take up a large part of the $2.5-million budget. Even for this relatively self-contained project, the work could take a long time and require a lot of resources. And the more money that gets spent on the traffic analysis studying the potential downsides, the less money that could be spent on community engagement, and analysis of what benefits the plan could bring.
That’s exactly why Replica developed its Road Closure Scenario Application — so that local agencies could get accurate, detailed traffic scenario outputs faster, and for less budget.
To demonstrate how it works, we ran a Road Closure Scenario that tested the impact of closing Wilshire Boulevard between South Alvarado and South Park View Streets, as the plan proposes.
We’re sharing the results below, organized around some of the top questions we designed the Road Closure App to answer:
1. How many and what kinds of trips would be impacted by the closure?
As previously noted, about 40,000 people drive through MacArthur Park on Wilshire every day. These 40,000 people make roughly 54,000 trips, as about 30% of those people make more than one trip using that road segment each day.
These trips, those that would need to be rerouted for the closure, make up just 0.1% of all trips in Los Angeles County. Some quick stats on these trips:
- These trips are generally not just very local, short distance trips. They have an average distance of 13 miles and average duration of 32 minutes.
- 23% of these trips are commutes and less than 1% of these trips are to school.
- These trips peak in the afternoon rush hour, with roughly 5,000 trips between 4 and 5 PM, more than any other hour.
When the road is closed, Replica’s Scenario suggests the impact on these commute trips is minimal. On average, the trips increase by less than a mile.
Meanwhile, it can be helpful to put those car trips in context of all of the bike and pedestrian activity in the area. In the area bounded by W 3rd Street, Union St, James M Wood Blvd, and S LaFayette Park Pl (roughly the square mile around MacArthur), there are more than 55,000 walking and biking trips each day, just outnumbering the number of car trips through the park.
2. What would be the spillover effect of the closure on the surrounding transportation network?
The short answer is: not much. As could be expected, volumes on Wilshire decrease significantly (more than 50% on the segments within half a mile of MacArthur Park on either side). And while volumes increase on W 6th (about 3.5x higher on the most affected link) and W 7th (about 2x higher), the impact is primarily contained to the segments in the immediate vicinity, with little spillover.
More importantly, as shown in the screenshots from the App below, even with the increased volumes on certain roads due to the closure, segments are not reaching max capacity. The App also makes it easy to understand which roadways are hitting capacity even in the existing traffic patterns, regardless of any proposed changes. Even on W 6th, where volumes increase more than anywhere else, average capacity utilization is still only at 51% in the afternoon when volumes are highest. (Within the Application it’s possible to drill down into this level of detail for each individual network link).
We even get insight into public transit impact. The bus traffic that typically passes through Wilshire is automatically rerouted to the closest alternative to accommodate a closure. In this case buses are diverted away from Wilshire from S Alvarado to S Hoover by instead taking South Alvarado, W 7th, and S Park View Streets. The diverted buses add little to no congestion to the diverted streets.
3. What are the demographic and socioeconomic characteristics of the people who would be impacted by the closure?
One of the benefits of Replica’s Road Closure Application is that it’s possible to run a scenario without losing the rich, trip-taker detail that is available in our core mobility data. Some highlights relevant to the proposal in LA:
- The trip takers who today drive through the to-be-closed portion of Wilshire have a median household income of $102,000, roughly the same as the $106,000 median of Los Angeles drivers as a whole, but twice as high as the median household income for Westlake residents ($53,000) who live in the immediate vicinity of MacArthur Park.
- The walkers and bikers in the area we noted in #1 show a similar income gap — with a median household income of $52,300, albeit people of all household incomes are shown as walking and biking in and around the park.
- Of the roughly 40,000 trip takers who drive through the to-be-closed portion of Wilshire, only 3,600 — less than 10% — live in Westlake. See the screenshot below for a map of the home zip codes of all 40,000 drivers.
Looking ahead, we hope that this type of rapid turnaround on road closure scenarios makes it easier for public agencies to better study more options for a wider range of projects, including for lane closures, temporary closures for construction that only take place during certain times of day, and mode-specific closures. If you're interested in obtaining a similar analysis for a project in your jurisdiction, reach out.
