Heinz Students Break Down Barriers to Urban Development in State Transportation Policies

Jul 29, 2014

Image associated with the Heinz Students Break Down Barriers to Urban Development in State Transportation Policies news item

In 2002, four southwestern Pennsylvania foundations formed a limited partnership with the Regional Industrial Development Corporation of Southwestern Pennsylvania (RIDC), a non-profit private development organization as general partner, and purchased the 178 acre LTV Steel Hazelwood site.  The partnership was convinced that this remarkable riverfront plateau offered a rare opportunity to set a new standard for urban riverfront property development. The name Almono came from the three Pittsburgh rivers - the Allegheny, Monongahela, and the Ohio.


The Almono Partners envision a master-planned development, maximizing local and regional impact, as well as employing development and economic "Best Practices" from across the globe.  Almono's focus on the long-term sustainability of the project is paramount to the planning effort.  Environmental sustainability, including alternate sources of energy, storm and waste water management and transportation innovation are key components of the plan.  The ownership's ability to be patient in terms of financial return, supports the Partnerships' goal of avoiding piecemeal, uncoordinated, or disconnected development.

There’s just one problem.  Permission for the planned development hinged on the results of a Traffic Impact Study required by PENNDOT.  Based on the study results, PENNDOT drew the conclusion that the Almono development would generate enough vehicular traffic on an already congested corridor to require substantive mitigation, and that this should take the form of thirty million dollars in additional infrastructure investments for ramp lengthening and street widening to accommodate the additional automobile traffic.

The Almono partnership politely disagreed and that’s where Heinz College came in.  RIDC teamed up with the College’s Traffic 21 Smart Transportation Institute which led to an MSPPM student project to assess of PENNDOT’s Transportation Impact Guidelines.  Advised by consultant Richard Feder, and an advisory board that included representatives from the Port Authority of Allegheny County, the Urban Development Authority of Pittsburgh, the Planning Department of the City of Pittsburgh, GAI Consultants, CMU’s Remaking Cities Institute, BikePGH, the Hazelwood Initiative, and Traffic 21 and RIDC, the students took a hard look of the appropriateness of TIS guideless for urban mixed use developments and using Almono as a case study, found a variety of ways such policies could be improved.

The team’s work focused on policies and procedures for trip generation estimates for mixed use developments, modal split estimation and assumptions, and the scope of acceptable mitigation strategies.

They began with a benchmarking of several state and large urban TIS guidelines.  The review found that, in fairness to PENNDOT, many states appear to use similar guidelines, often relying on the same standardized methods and assumptions.  For example, many state guidelines for trip generation rely on the Institute of Transportation Engineers’ (ITE) Trip Generation Manual.  But common criticisms of the ITE are that its models are not sensitive to specific cases of mixed use developments, that they are dependent on data from suburban and exurban locations rather than urban sites, and that they only generate automobile traffic, not public transit, bicycle, or walking trips.

Next, the team then identified some alternative approaches to develop trip generation and modal split estimates for the Almono development and ran some numbers.  They settled on the EPA’s Generation Tool for Mixed Use Developments (the MXD model), which among other advantages is sensitive to the land uses of mixed use development, and the potential interactions between them, (such that, for example, some shopping trips for residents on the site might be captured by retail on the site with a walk, rather than a drive to store elsewhere).  MXD also produces trip generation estimates for public transit and walk/bike trips. For a full build out scenario of Almono, their first pass at the MXD tool indicated a 24% reduction in projected automobile traffic compared to the standard ITE approach.

Then the team examined PENNDOT’s guidelines for estimating the modal split of generated trips (auto, bicycle, transit, etc.).  They found that PENNDOT allows the use of an array of general adjustment factors to account for the presence of conditions that might encourage increased transit or bike/walk trips such that vehicular traffic is reduced, and noted that PENNDOT’s guidelines also allow for the use of transit studies (for Philadelphia and Pittsburgh only) to assess the likely effectiveness of case specific strategies to increase the use of alternative modes.  Along those lines, based on an examination of data from the American Community Survey, projections from the Southwestern Pennsylvania Commission, and real time data from Automatic Passenger Counter systems from Port Authority, the team reached two conclusions. One, the City and region are already achieving shares of alternative modes (walking, transit, bicycling) than are allowed for in the PennDOT guidelines. This directly indicates that current guidelines significantly overestimate automobile trips. Two, concrete steps to increase the use of transit to and from the site ought to be considered, including restoring bus service (cut back earlier this year as part of a system-wide retrenchment by Port Authority, limiting and charging for on site parking, and encouraging on site employers to partner with Port Authority for free transit pass programs.

Finally, the team took a hard look at alternative mitigation strategies to the proposed $30 million in infrastructure required by PENNDOT, both based on the literature and the experience of three other successfully developed brownfield sites in the city: Southside Works, The Waterfront, and the recent Bakery Square development.  One of their most remarkable discoveries, well known to all parties, was that the intersections in the area of the Almono site are already congested enough with auto traffic to warrant (under PENNDOT guidelines) substantive intervention…and construction has yet to begin!  This raised interesting questions on the utility of past policies to prevent such congestion, and the fairness of requiring the partnership to pay for the congestion generated by past development.  Using Google Live data, the partnership was able to assess the success of a range of traffic mitigation strategies (from cheap to expensive) at the Waterfront and Bakery Square brownfield sites, including signage, signalization, signal optimization, turning lanes new roads and extensions.  In short, what they found is that more often that not, depending on the impacted intersection and time of day (AM/PM peak hours), years after both major developments were complete, levels of service (LOS…a.k.a congestion and waiting times)  either held steady or marginally improved.  This occurred in the presence of lower cost mitigation strategies, strong levels of transit service, and favorable conditions for pedestrian travel.

Their final report included a warning that previous estimates of auto trip generation may be overstated, and the alternative mode split may be underestimated.  In terms of traffic impact mitigation strategies for Almono, in addition to enhanced transit service, they recommended increased bicycle infrastructure, employer transportation management strategies, and complete street ordinances.  The report concluded with an observation on public policy, that the City of Pittsburgh is empowered to adapt its own TIS guidelines if it wanted to.

This system project is just one of several related to transportation policy in the Pittsburgh region that Heinz students have tackled.  Other recent examples include “Putting Intelligent Transportation to Work” and “The Community and Economic Impacts of Bus Rapid Transit”, both for Port Authority of Allegheny County.


Interested in supporting Heinz College students and initiatives like those featured in this story? Click here for more information.