Do high visibility crosswalks improve pedestrian safety? A correlated grouped random parameters approach using naturalistic driving study data

Addressing unobserved heterogeneity in the analysis of bicycle crash injuries in Scotland: A correlated random parameters ordered probit approach with heterogeneity in means

“…Where β denotes the mean value of the random parameters vector, Γ denotes the Cholesky matrix used for the estimation of the covariance matrix for the random parameters (see also Greene, 2016;Fountas et al, 2018a;2018b;Pantangi et al, 2020 for more details on the process of the Cholesky decomposition), C represents a vector of covariates determining the means of the random parameters, i.e., the variables capturing heterogeneity in the means (Eker et al, 2019;Al-Bdairi et al, 2020;Hamed and Al-Eideh, 2020;Ahmed et al, 2020;Yan et al, 2021), λ is a vector of coefficients, ω represents a random term, which follows the standard normal distribution (Washington et al, 2020). The incorporation of the λC term constitutes an important feature of Equation ( 2), as it allows the identification of unobserved effects, which differ from those captured by the random parameters but interact with them.…”

Solar-Powered Active Road Studs and Highway Infrastructure: Effect on Vehicle Speeds

“…For example, this phenomenon has been associated with interventions such as seat belts, anti-lock brakes, and the implementation of street lighting [29][30][31]. In the specific case of solar-powered road studs, if increases in driver confidence [17] were to translate to a corresponding increase in mean speed, this could result in increased crash rates [9][10][11][12][13][14]. The relationship between active road studs, other road features, and speed is therefore of considerable interest.…”

“…More recent research has tended to look at the road level (including segments, sections, intersections, and corridors), rather than individual driver level, not least because of the difficulties of categorically associating speed as a causation factor in individual crashes [8]. The question then becomes one of how the frequency and severity of the crashes vary with mean speed, to which the answer has been extensively explored; before-and-after studies of measures, such as changes in the posted speed limit, traffic calming interventions, or increased enforcement have resulted in linear, power, and asymptotic relationships associating higher mean speeds with increased crash rates [9][10][11][12][13][14]. Therefore, from the point of view of the road designer, road features that result in unintended increases in mean speed are unlikely to be desirable.…”

Are we willing to relocate with the future introduction of flying cars? An exploratory empirical analysis of public perceptions in the United States

“…The latter allow the estimable parameters to vary across groups of distributor-specific responses. Grouped random parameters are defined as (Dong et al, 2016;Murillo-Hoyos et al, 2016;Sarwar et al, 2017a;Fountas et al, 2018a;Fountas et al, 2018b;Fountas et al, 2019;Pantangi et al, 2019;Pantangi et al, 2020;Intini et al, 2020;Pantangi et al, 2021;Ahmed et al, 2021b):…”