For the last year, a series of reports from the Los Angeles Times has examined the patterns of new and existing residential developments in close proximity to Southern California freeways. An analysis found that some 1.2 million people live within a 500-foot radius of a major highway - prompting calls from both the City Council and City Planning Commission for a report on existing practices to combat freeway pollution, as well as recommendations for improved strategies.

In a memo referred last week to the Council's Planning and Land Use Management Committee, the Planning Department lays out several strategies to reduce exposure to air pollutants, including:

Installation and regular maintenance of high-efficiency filters

Although high-efficiency air filters are often required at many freeway-adjacent apartments as a condition of approval, installation and maintenance must typically be carried out by private developers.

For properties under the control of the City of Los Angeles, the Planning Department report states that preliminary discussions with the Housing and Community Investment Department indicate that periodic inspections of filters could be possible if the equipment was "centrally located."

The report also suggests providing information and guidance to private developers as a way to improve their use and maintenance of air filters.

Limitations on the siting of sensitive uses immediately adjacent to the freeway

The report calls for a 1,000-foot buffer area surrounding freeways in which sensitive uses - including daycares and schools - could be prohibited.

As many Angelenos already live within these areas, many of which were developed as residential neighborhoods long before the construction of the freeways, it is deemed infeasible to limit residential uses within the 1,000-foot buffer. The Planning Department recommends that policymakers consider freeway-adjacency when approving land use and zoning changes.

The report also notes that both the Planning Commission and the Planning Department have responded to concerns about freeway-adjacent developments by mandating a Health Risk Assessment for certain projects. Most of these assessments - which can cost up to $20,000 - recommend the use of high-efficiency filters. The Department considers this to be a potentially cost-prohibitive solution, as the City's Clean Up Green Up ordinance already mandates filters at freeway-adjacent developments.

Design, building location and installation of landscaping screens

The report cites expert recommendations that balconies, outdoor amenity spaces, and occupied portions of buildings be located as far away from a freeway as possible. However, it is difficult to propose a blanket regulation given the variety of freeway-adjacent properties across the city.

Although landscape screens have been discussed as a potential mitigation measure for airborne pollutants, the Department cites research that finds that some landscaping can trap pollutants rather than screen them.

Strategies to Reduce Mobile Source Emissions

The most promising strategies for reducing mobile source emissions, according to the Department's discussions with consultants in several fields, is to reduce vehicular miles traveled and to promote clean technology vehicle infrastructure.

The Department recommends leveraging ongoing transportation investments by Metro to increase the intensity of development around transit stations, reduce parking requirements in this area, and create a public realm that is conducive to walking, cycling, and transit use.

The report also calls for continued steps toward reducing tailpipe emissions, including the expansion of electric vehicle charging stations in public and private buildings, and working with the Port of Los Angeles to transition toward clean fuel and electric vehicles.