A note on transit time and reliability for regular-route trucking

Synchromodal transportation planning using travel time information

“…The resulting average speed of this distribution is approximately 60 km/h and is consistent with Ambra et al (2019a). We used the binomial distribution in line with Chiang & Roberts (1980), who proposed right-skewed distributed travel times for road transportation.…”

“…The minimum travel times of road transportation are driven by a maximum average speed of 70 km/h, which was reported by Demir et al (2017) in absence of congestion. We used Chiang & Roberts (1980) to validate the rightskewed binomial distribution. The binomial distribution applied in our numerical study implies an average speed of approximately 60 km/h for road transportation, which is consistent with the average speed reported 565 by Ambra et al (2019a).…”

Analysis of intermodal freight from China to Indian Ocean: A goal programming approach

“…The fact that size and weight are not considered in the estimations represents a shortcoming because large or heavy cargoes tends to cost more than small or light cargoes (even though the freight values may be the same). Fourthly, the model in Chiang and Roberts (1980) is used to estimate the unknown transit time by truck. As Chiang and Roberts had limited their analysis to industrial and private carriers on regular routes, the applicability of their model may be limited in the case where relationships between transportation distance and transit time are unclear.…”

“…(2), T ijk is influenced by factors such as distance, load weight and number of stops. Under circumstances that transit time by truck may not be clearly or directly identified, Chiang and Roberts (1980) proposed a Gamma probability distribution to estimate the transit time and its variance of the given distance, as Eqs. (3) and (4).…”

Vehicle routing with soft time windows and Erlang travel times

“…The distinguishing feature of this problem lies in the stochastic nature of the travel times; even if the routes are assigned such that the 'expected' arrival time falls within the time window of a customer, the variability in travel times results in some probability of arriving outside the time window and incurring an associated penalty. Chiang and Roberts (1980) developed an empirical model to predict the transit time for regular-route, less-than-truckload trucking between two points. They found that a minimum travel time exists (using reasonable speeds) and that the distribution tends to be skewed toward longer travel times.…”