National Institute for Transportation and Communities

The video begins at 2:06.

Abstract: The most fundamental need in a bicycling network is low-stress connectivity, that is, providing routes between people’s origins and destinations that do not require cyclists to use links that exceed their tolerance for traffic stress, and that do not involve an undue level of detour. Evaluating network connectivity therefore requires both a set of criteria for tolerable levels of traffic stress and measures of connectivity appropriate to a bikeway network. 

We propose criteria by which road segments can be classified into four levels of traffic stress (LTS), corresponding to four levels of traffic tolerance in the population. LTS 1 is suitable for children; LTS 2, based on Dutch bikeway design criteria, represents the traffic stress that most adults will tolerate; LTS 3 and 4 represent greater levels of stress. As a case study, every street in San Jose, California was classified by LTS. Maps in which only lower stress links are displayed reveal a city fractured into low-stress islands separated from one another by barriers that can only be crossed using high stress links. 

To measure connectivity, two points in the network are said to be connected at a given level of traffic stress if there is a path connecting them that uses only links that do not exceed that level of stress and whose length does not exceed a detour criterion (25% longer than the most direct...

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Summary: Researchers from the transportation, planning and health fields share the common goal of promoting physically active lifestyle. One challenge that researchers often face is the measurement of physical activity, particularly among children. This is because the sporadic nature of children’s physical activity patterns makes it difficult to recall and quantify such activities. Additionally, children’s lower cognitive functioning compared to adults prevents them from accurately recalling their activities. This presentation will describe the design and application of a novel self-report instrument - the Graphs for Recalling Activity Time (GReAT) - for measuring children’s activity time use patterns. The instrument was applied in a study of children’s risk for obesity and diabetes in a predominately Hispanic community in Milwaukee, WI. Time-use data for two weekdays and one weekend day were collected for various physical and sedentary activities. The data was then assessed against measurements of the children’s cardiovascular fitness, weight status and insulin resistance through exploratory analysis and structured equation modeling. Findings on GReAT’s reliability and new evidence on the impacts of time-use in different activities on children’s risk for...