Analysis grid superimposed 2D Street Grid Calculating Travel-Time …vector to raster conversion Note that a 100 row by 100 column analysis grid (10,000 cells) is superimposed on the street data and those cells containing a road are assigned a friction value representing the typical time to traverse each location– primary streets (red) = 8.5 seconds; secondary streets (blue) = 25.5 seconds.

2D Street Grid 3D Street Grid Calculating Travel-Time …street types as relative barriers Note that the street pattern can be displayed as 2D and 3D plots. The street pattern can be conceptualized as a canal network that connects Kents Emporium to its customers. Kents Emporium

2D TTime_0-10 3D TTime_0-10 Calculating Travel-Time …splash 0-10 cells = 0 to 1.4 minutes Base cell = 8.5sec =.1424min Note that the distance waves begin to move away from Kents Emporium along the canal pattern (streets) like ripples from a rock tossed into the water. The distance waves accumulate the time it takes to cross each grid cell– considering the relative impedance for primary (8.5sec) and secondary (25.5sec) streets.

2D TTime_0-20 3D TTime_0-20 Calculating Travel-Time …0-20 cells = 0 to 2.8 minutes Base cell = 8.5sec =.1424min

2D TTime_0-30 3D TTime_0-30 Calculating Travel-Time …0-30 cells = 0 to 4.3 minutes Base cell = 8.5sec =.1424min

2D TTime_0-40 3D TTime_0-40 Calculating Travel-Time …0-40 cells = 0 to 5.7 minutes Base cell = 8.5sec =.1424min

2D TTime_0-50 3D TTime_0-50 Calculating Travel-Time …0-50 cells = 0 to 7.1 minutes Base cell = 8.5sec =.1424min

2D TTime_0-60 3D TTime_0-60 Calculating Travel-Time …0-60 cells = 0 to 8.5 minutes Base cell = 8.5sec =.1424min

2D TTime_0-70 3D TTime_0-70 Calculating Travel-Time …0-70 cells = 0 to 10.0 minutes Base cell = 8.5sec =.1424min

2D TTime_0-80 3D TTime_0-80 Calculating Travel-Time …0-80 cells = 0 to 11.4 minutes Base cell = 8.5sec =.1424min

2D TTime_0-90 3D TTime_0-90 Calculating Travel-Time …0-90 cells = 0 to 12.8 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-100 Calculating Travel-Time …0-100 cells = 0 to 14.2 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-110 Calculating Travel-Time …0-110 cells = 0 to 15.7 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-120 Calculating Travel-Time …0-120 cells = 0 to 17.1 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-130 Calculating Travel-Time …0-130 cells = 0 to 18.5 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-140 Calculating Travel-Time …0-140 cells = 0 to 20.0 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-150 Calculating Travel-Time …0-150 cells = 0 to 21.4 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-160 Calculating Travel-Time …0-160 cells = 0 to 22.8 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-170 Calculating Travel-Time …0-170 cells = 0 to 24.2 minutes Base cell = 8.5sec =.1424min

2D TTime_ D TTime_0-180 Calculating Travel-Time …0-180 cells = 0 to 25.6 minutes Base cell = 8.5sec =.1424min

Results displayed in a Desktop Mapping system (raster to vector) 2D TTime_0-180 Calculating Travel-Time …0-180 cells = 0 to 25.6 minutes Base cell = 8.5sec =.1424min Note that of the 10,000 cells comprising the analysis grid, 4123 do not contain a road. Of the 5877 cells with a road, 3014 locations (a little over 50 percent) are 0 to 70 effective cells away, or about 10 minutes from Kents Emporium (non- shaded area of the summary table)

Calculating Travel-Time For more discussion on travel-time calculation and its applications, visit… …educational software for hands-on experience in creating and using travel- time maps and other grid-based map analysis …online book discussing travel-time concepts, procedures and considerations (Topics 5, 6, 13,14 and 17), as well as other grid-based analysis techniques …also see Papers/Presentations Online Papers, select Understanding Effective Distance and Connectivity