1. Network Development and Zone Definition
CE 451/551

2. Network Development and Zone Definition
What factors impact the design of TAZ boundaries?
What link attributes are required for network coding?
What types of networks are used in TDF?
What steps of the TDF process are networks used for?

3. Centroids, centroid connectors, external stations, links, networks, nodes, zones (TAZs), districts

4. TAZ definition: consistency, census, network, barriers, homogeneous land use, rule of thumb per population

5. Centroids no yes Future??? Centroid = center of activity … future?
Centroid connectors = representation of roads … future?
Future???

6. Networks used in what steps?
Networks used in what steps? Gen? (access); dist/mode/assign
Highway, transit, HOV …

7. Network versions Base year E+C Interim years Adopted Plan Alternatives
Time of day
Base: calib/valid
E+C: TIP

8. Sample network attributes
Nodes: x,y,type,penalty, prohib, delay
Links: fnode, tnode, 1way, length, type, lanes, area type, cap, speed, transit route
Nodes: x ,y, type, penalty, prohib, delay
Links: fnode, tnode, 1way, length, type, lanes, area type, cap, speed, transit route

11. access links
Same zone structure? Implications?

12. Lookup vs. individual coding; facility type (functional class, define)
+ area type = speed/cap; define functional classes – give example
Area type: CBD, CBD fringe, mixed urban, non-cbd business, sub/res, rural

13. Selecting network from line file …

14. Disabling links … why?

15. Network “skims”
Distribution, assignment; output is a matrix of travel time or “skims”

16. Turn penalties/prohibitors

17. Route through centroids?