|M.Sc Student||Ron Mishory|
|Subject||A New Road Connectivity Index and Application as An|
Evaluator for Transportation Planning.
|Department||Department of Architecture and Town Planning||Supervisor||Professor Gat Daniel|
The purpose of this study is to formulate and test a new index for road network connectivity at the national or regional level. The uniqueness of the proposed index stems from its construction procedure which includes the connectivity estimation of single settlements, making it possible to measure the spatial variability of connectivity. Thus, the aims of the research are:
1. To propose a new simple index of connectivity which reflect the level of national road network advancement.
2. To associate with the above an index of spatial equity of connectivity.
3. To validate the index by correlating it with socio-economic index.
4. To examine, by applying the new index, the development of Israel’s road network over time, and to compare it with other countries.
5. To provide planners with an evaluation tool, enabling:
A. Ex post evaluation: evaluating an existing state by comparison with an earlier state.
B. Ex ante evaluation estimating a planned improvement compared with an existing state.
C. Evaluation of local improvements: improvements in connectivity of specific towns or regions.
The research tests the following hypothesis:
1. Nations with high (low) levels of economic development have high (low) index of connectivity.
2. Nations with high (low) levels of economic development have low (high) indexes of connectivity Inequity.
3. Israel’s road network development effort has led to a higher relative improvement in places which were, to begin with better connected.
Computing the connectivity index: The proposed indexes are computed in four steps
1. Computing the distance or travel-time ratio (ideal to actual) between each origin and each destination.
2. Computing the connectivity index of each origin to the rest of the county.
3. Computing the country-wide connectivity index.
4. The fourth step produces the connectivity inequity index named as the weighted deviation. The resulting connectivity index falls between zero and one. The closer to one, the higher the network connectivity. The connectivity inequity index is computed in a way similar to that of standard deviation, taking into account the population weight of each city.
Findings: Over the period 1955-1992, the connectivity index for Israel has grown by 7%, from a value of 0.67 to 0.72, as a result of new road construction and enhancement of existing roads, thus raising their travel velocity. During the same period the connectivity inequity index has worsened and grew by 33% from a value of 0.045 to 0.060. A sample of nations was chosen for a two-fold purpose: To compare connectivity with that of Israel, and to seek a correlation between G.N P and connectivity. Such a correlation was found to be 0.71 ( r2 50%). Several year - 2000 scenarios were suggested for improving Israel’s road network. The highway 6 scenario was found to improve connectivity (from the year -1992 base) by 8%, bringing it to a value of 0.78. The suggested connectivity index may serve International bodies such as The U.N or The World Bank to evaluate and rank nations applying for road building grants.