NETWORK EQUILIBRIUM MODELS OF URBAN LOCATION AND TRAVEL CHOICES: A RETROSPECTIVE SURVEY*

ABSTRACT The origins and development of the network equilibrium problem are traced and interrelated. Two principal formulations are considered the network equilibrium problem with variable travel demand, and the combined model of trip distribution and traffic assignment. The relation of these models to subsequent developments concerning mode choice, residential location, estimation of origin-destination tables from link flows and stochastic route choice are then reviewed.     

Aid Conditionality as a Tool for Peacebuilding: Opportunities and Constraints

Over the past decade, aid donors have pledged billions of dollars to support peacebuilding efforts in collapsed states and war–torn societies. Peace conditionality — the use of formal performance criteria and informal policy dialogue to encourage the implementation of peace accords and the consolidation of peace — could make aid a more effective tool for building peace. In Bosnia, for example, donors have attempted to link aid to the protection of human rights, co–operation with the international war crimes tribunal, and the right of people displaced by ‘ethnic cleansing’ to return to their homes. Yet the conventional practices and priorities of aid donors pose constraints to the exercise of peace conditionality. This article examines several of these constraints, including the reluctance of donors (particularly the international financial institutions) to acknowledge responsibility for the political repercussions of aid; the competing foreign–policy objectives of donor governments; the humanitarian imperative to aid people whose lives are at risk; and the incentive structures and institutional cultures of donor agencies.     

Congo's Odious Debt: External Borrowing and Capital Flight in Zaire

During the dictatorship of Mobutu Sese Seko, Congo (or Zaire, as Mobutu renamed the country) accumulated a public external debt of roughly $14 billion. At the same time, Mobutu and his associates extracted wealth from the country. By 1990, real capital flight from Zaire amounted to $12 billion. With imputed interest earnings, the accumulated stock of Zairian flight capital was nearly $18 billion. Congo's successor governments may be able to repudiate liability for the Mobutu regime's debts on the basis of the doctrine of odious debt. Creditors could then seek to recover their losses by identifying and impounding flight capital which was extracted from the country.     

Book reviews

PARTY LEADERSHIP AND REVOLUTIONARY POWER IN CHINA. John Wilson Lewis (ed.) Cambridge University Press, 1970. viii, 422 pp. 25s.

CONFLICT ANALYSIS. Michael Nicholson. English Universities Press, 1971. viii, 168 pp. £1.45 (29s.).

PHILIPPINE NATIONALISM. EXTERNAL CHALLENGE AND FILIPINO RESPONSE, 1565–1946. Usha Mahajani. University of Queensland Press, 1970. xv, 530 pp. $12.00.

THE SIEGE OF THE PEKING LEGATIONS: A DIARY. Lancelot Giles. With introduction: CHINESE ANTI‐FOREIGNISM AND THE BOXER UPRISING. L. R. Marchant (ed.). University of Western Australia Press, Nedlands, Western Australia, 1970. xxvii, 212 pp. $9.60.

MICROSTATES AND MICRONESIA: PROBLEMS OF AMERICA'S PACIFIC ISLANDS AND OTHER MINUTE TERRITORIES. Stanley A. de Smith. New York University Press, 1970. 193 pp. $7.50.

NEW ZEALAND AND AUSTRALIA: FOREIGN POLICY IN THE 1970s. Bruce Brown (ed.). Price Milbum, Wellington, for the New Zealand Institute of International Affairs, 1970. 91 pp. $1.50.

LANG AND SOCIALISM. Robert Cooksey. Australian National University Press, 1970. xiii, 96 pp. $2.50.

THE ARMY IN PAPUA‐NEW GUINEA. Robert J. O'Neill. Australian National University Press, 1970. 31 pp. $1.50.

A HISTORY OF MALAYA. J. Kennedy. Macmillan Student Editions, London, 1970. xi, 364 pp. $3.40.

LENIN'S CHILDHOOD. Isaac Deutscher. Oxford University Press, Melbourne, 1970. 67 pp. $4.25 hard cover.

SELECTED LETTERS OF HUBERT MURRAY. Francis West (ed.). Oxford University Press, Melbourne, 1970. 255 pp. $6.50.     

Validation of Multiclass Urban Travel Forecasting Models Combining Origin–Destination, Mode, and Route Choices

Abstract The formulation, estimation, and validation of combined models for making detailed urban travel forecasts are described. These models combine origin–destination, mode, and auto route choices into a consistent forecasting method for multiple user classes for the Chicago Region. Household Travel Survey and Census Transportation Planning Package data for 1990, respectively, are used to estimate and validate the model.     

Infiltration of basinal fluids into high-grade basement, South Norway: sources and behaviour of waters and brines

Quartz veins hosted by the high‐grade crystalline rocks of the Modum complex, Southern Norway, formed when basinal fluids from an overlying Palaeozoic foreland basin infiltrated the basement at temperatures of c. 220°C (higher in the southernmost part of the area). This infiltration resulted in the formation of veins containing both two‐phase and halite‐bearing aqueous fluid inclusions, sometimes with bitumen and hydrocarbon inclusions. Microthermometric results demonstrate a very wide range of salinities of aqueous fluids preserved in these veins, ranging from c. 0 to 40 wt% NaCl equivalent. The range in homogenization temperatures is also very large (99–322°C for the entire dataset) and shows little or no correlation with salinity. A combination of aqueous fluid microthermometry, halogen geochemistry and oxygen isotope studies suggest that fluids from a range of separate aquifers were responsible for the quartz growth, but all have chemistries comparable to sedimentary formation waters. The bulk of the quartz grew from relatively low δ¹⁸O fluids derived directly from the basin or equilibrated in the upper part of the basement (T < 200°C). Nevertheless, some fluids acquired higher salinities due to deep wall‐rock hydration reactions leading to salt saturation at high temperatures (>300°C). The range in fluid inclusion homogenization temperatures and densities, combined with estimates of the ambient temperature of the basement rocks suggests that at different times veins acted as conduits for influx of both hotter and colder fluids, as well as experiencing fluctuations in fluid pressure. This is interpreted to reflect episodic flow linked to seismicity, with hotter dry basement rocks acting as a sink for cooler fluids from the overlying basin, while detailed flow paths reflected local effects of opening and closing of individual fractures as well as reaction with wall rocks. Thermal considerations suggest that the duration of some flow events was very short, possibly in the order of days. As a result of the complex pattern of fracturing and flow in the Modum basement, it was possible for shallow fluids to penetrate basement rocks at significantly higher temperatures, and this demonstrates the potential for hydrolytic weakening of continental crust by sedimentary fluids.