Date of Award

Spring 1-1-2017

Document Type

Thesis

Degree Name

Master of Engineering (ME)

Department

Civil, Environmental & Architectural Engineering

First Advisor

Charles W. Beamer IV

Second Advisor

Keith Molenaar

Third Advisor

Bernadette Park

Fourth Advisor

Sandra Vasconez

Abstract

Denver's 16th Street Mall was first introduced as the retail and commercial heart of the city in the 1980’s through the distinctive design of I.M. Pei and Partners. However, in recent years, the need for a revitalization through an ambitious urban renewal plan has become apparent as years of "wear and tear" combined with rapid urban growth and development have begun to take a toll on the beloved mall. In recent years, the City of Denver has allocated funds to renovate this Central Denver corridor, in an effort at revitalizing this urban area. One of the central components of this urban renewal plan is the replacement of the existing, out-of-date lighting fixtures with new, LED replica fixtures. This document provides an in depth analysis of the impact of the 16th Street lighting retrofit installation through the extensive documentation of both pre and post installation lighting conditions.

The purpose of this study is to document the changes that occur as a result of the installation and draw a conclusion about the impact of the new lighting on the mall from both an objective and subjective point of view. The objective components of the study included taking extensive lighting measurements on the mall both before and after the installation to document the physically calculable changes to the lighting on the mall. These measurements included horizontal illuminance, vertical illuminance, and luminance via High Dynamic Range (HDR) images. The subjective, or human factors, components of the study included surveying users of the mall before and after the installation, in order to get an understanding of user preferences and opinions with the goal of understanding of how peoples’ perceptions of the light has changed. This component focused on understanding the changes in lighting characteristics which impact the perceptions of the user such as light quality, reassurance or perceived safety, and visual performance. Together, the objective and subjective results were combined to gain a comprehensive understanding of the effect that the new lights have had on the mall and those who use it.

This results of this study are that the overall light levels on the mall decreased as a result of the new lighting installation. However this decrease was not perceived by the mall uses likely because perception of brightness was shown to have increased. The subjective analysis revealed that the visual performance of mall users increased despite the reduced light levels. The increased perception of brightness and the improved ability to perform visually may have been caused by the dramatic colorimetric changes that resulted from transitioning from High Pressure Sodium to LED light sources. This resulted in a significant increase in both color temperature as well as color rendering ability although the subjective analysis did not reflect these changes. The new lighting was also showed to have improved the distribution of light on the mall, making it more uniformly distributed on the sidewalk. The increased uniformity, along with the changes in color properties, may be the cause of the increased feelings of perceived safety and reassurance on the mall. The new lighting did not show any changes in visual comfort, perceptions of luminous atmosphere, or general mall usage. This study serves as a starting point for more in-depth studies of a similar nature as well as an outline for other studies that wish to observe similar, large-scale, exterior lighting changes.

Share

COinS