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Highlights • This study investigated the effect of speed limits increases on fatalities. • A meta-analysis was carried out of a sample of regression studies for the US. • Count fatalities went up more on rural interstates than all roads network. • Statewide fatality rates per VMT would relatively improve although weakly. Abstract Speed plays an important role in road safety as it affects accident risk and severity. Among safety policies implemented to control driving speed, speed limits are the most highly developed. Since the 1970′s, numerous studies have focused on the effectiveness of speed limits, but even today there is still no clear consensus as to the impact that raising the speed limit has on traffic fatalities. With the aim of consolidating knowledge on this topic, a meta-analysis has been carried out of a set of econometric studies assessing the effects on traffic fatalities of increasing speed limits in the US. Two sub-samples were obtained, taken from the traffic fatality measures considered by studies (fatality count and fatality rate normalized per vehicle miles traveled), and two approaches were analyzed: rural interstates (where speed limits were increased in 1987 and 1995), and a statewide approach (all roads network). Our findings show that by count traffic fatalities went up on both rural interstates and statewide level, although the effect was higher on rural interstates. In other respects, statewide fatality rates could be improved in relative terms by raising legal speed limits, although the effect would be weak. [ABSTRACT FROM AUTHOR]

An increasing number of studies have addressed the impact of Audience Response Systems (ARS) on academic performance at all stages of education, although the evidence does not seem conclusive. With the aim of shedding light on the extent and diversity of the research outcomes, we conduct a meta-analysis of studies worldwide on this topic to assess whether the exam scores of students included in ARS experiments achieve better results than others taught using more conventional teaching tools. From an initial sample of 254 studies, data from 51 papers published between 2008 and 2012 (involving 14,963 participants) that set academic quality criteria, were extracted and analyzed following technical protocols for meta-analyses. Their high degree of heterogeneity shows that the effect of ARS on exam scores seems to be moderated by specific features. So, through a random-effects model, our results provide a positive, although moderated pooled effect of ARS on examination scores that is much greater in experiments performed in non-university contexts (Hedges' g = 0.48; S.E. = .2665) than at the university level (Hedge's g = 0.22, S.E. = .0434). Specifically, the categories of university disciplines in which ARS interventions are implemented seem to influence their usefulness for achieving better academic marks, being more effective when either Pure Soft Sciences or Applied Hard Sciences are considered. These findings might provide guidance for governments, researchers and educators into the effectiveness of learning based on the new interactive technologies. [ABSTRACT FROM AUTHOR]