Measures of Speeding from a GPS-based Travel Behavior Survey

Objective: Lacking information about actual driving speed on most roads in the Minneapolis - St. Paul region, we determine car speeds using observations from a GPS-based travel survey. Speed of travel determines the likelihood of, and consequences of, collisions. We identify the road segments where speeding occurs. This paper then analyzes the relationship between road network structure, traveler characteristics, and speed- ing using GPS data collected from 152 individuals over a 7 day period as part of the Minneapolis - St. Paul Travel Behavior Inventory. Methods: To investigate the relationship, we employed an algorithm and process to match the GPS data with GIS databases accurately (1). Comparing actual travel speed from GPS data with posted speed limits, we measure where and when speeding occurs, and by whom. We posit that road network structure and demographics shape the decision to speed. Results: Speeding is widespread in both high speed limit zones (e.g. 60 mph (97 km/h)) and low speed limit zones (less than 25 mph (40 km/h)); in contrast, speeding is less common in the 30 - 35 mph (48-56 km/h) zones. The results suggest driving patterns depend on the road type. We also find that when there are many intersections on the road, the average link speed (and speeding) drops. Long links are conducive to speeding. Younger drivers, and more educated drivers also speed more, and speeding is higher in the evening. Conclusions: Road design and network structure affects the likelihood of speeding. Use of increasingly available GPS data allows more systematic empirical analysis of designs and topologies that are conducive to road safety

Pavement condition and crashes

Change in weather state (such as the freeze-thaw cycle) leads to distresses in pave- ment materials. It has been hypothesized that poor pavement quality reduces the ability of roads to drain and reduces the ability of vehicles to resist skidding, and is thus associated with more crashes. This paper combines GIS data on crashes with a separate GIS database to test the hypothesis. Poor road quality is associated with more property damage and injury crashes. The interaction of road quality and curves was surprising, indicating that good pavement quality on curves increased the fatal, injury, and property-damage crash rate

Genetic characterization of ayu Plecoglossus aliivelis aliivelis occurred in Nakaumi Lagoon

Ayu Plecoglossus altivelis altivelis is a common fish that is composed by two major forms, amphidrDmOuS and landlocked forms, based on itsannual1ife history. Althoughrecent decline in the reserves of amphidromous stocks in rivers has prompted frequent transplantations from landlocked stocks, a low survival rate of larvae of the landlocked fbm occllrS during periods of high water temperature in seawater. In brackish water environment, however, non-native landlocked form may survive and show sympatric distribution with mother populations. This study was conducted to verifythe genetic status of ayll 0cclmed in Nakaumi Lagoon, which is the second largest brackish lake in Japan. Nucleotide sequence polymoIPhism of the first 300 bp of themitochondrial DNA control region Was analyzed for 30 individuals including each 15 Specimens collected from 2 locales ofNakaumi Lagoon in May 2009, along with each 15 reference specimens oftheamphidromous and landlocked stocks. Comparatively high1evels of nucleotide substitution were observedwith 35 polymoIPhic sites from Nakatlm population and 40 sites from the amphidromous stock, as contrasted with24 sites from the landlocked stock. Based on nucleotide sequences at 5 hypervariable sites, 2 haplotypes occured in only the amphidromousstock were obtained at a high frequency in Nakaumi Population These results suggest that the amphidromous form forms the majority of Nakaum population.Article信州大学山地水環境教育研究センター研究報告 6: 125-132(2010)departmental bulletin pape

Resource constrained distributed constraint optimization with virtual variables

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Population genetic structure ofYamato-sllijimi clam in Lake Sbinji, Japan

Yamato-shijimiclam Corbicula japonica is the best-known bivalve inhabiting ln brackish estuaries and lakes around Japan and one of the most commercially important species in inland fisheries. Althoughthe amotmt of C japonica from Lake Shinji has accotmted for the large part of the domestic catch, itsamolmt has dramatically fallen in recent years･ This study was conducted to verifythe genetic structtue and reproduction mechanism of C･ japonica, both of which are essential to its stock management in Lake Shinji. Weanalyzed sequence polymorphism of the 588 bp portion ofthemitochondrial DNA cytochrome oxidase subunit I (Col) gene to determinethe population genetic structure of C･ japonica in Lake Shinji･Among a total of 177 C･ japonica specimens collected from 4 colonies, 37 haplotypes were obtained, and 2 major haplotypes were apparent withrelatively highabtmdance in all colonies･ Well correspondingmismatch distributions along the Col gene were determined for the data sets of the individual colonies, and the pairwise population estimates FsT among the individual colonies were also generally low, Such small genetic differentiation of C japonica is derived kom highgeneflow in Lake Shinji, and this could be caused by a lake-wide dispersion of its larvae mediated by the water movements･Article信州大学山地水環境教育研究センター研究報告 6: 115-124(2010)departmental bulletin pape