Perspectives on Transport Management from London, Stockholm & Paris Rémy Prud’homme (Un. Paris XII) Imperial College, London, Jan. 17, 2007

Three urban transport policies Much publicized London: an area toll in a small (3% in pop.) part of the agglomeration Paris: a reduction in road space in a larger (20%) part of agglomeration Stockholm: a cordon toll in a similar (15%) part of agglomeration Lessons from such policies

An apparent success ? In all three cases, stated objective of traffic reduction achieved, by some 15% For the media: enough to call it a success Take a second look

Two effective benefits in London & Stockholm time gains + environmental gains S(q) I(q) Unit costs Quantities q1q2 D(q) Time gain Surplus loss A Toll c2 c1 B

No Benefits in Paris No time gains, only time losses I1(q) I2(q) q q1q2 c2 c1 D(q) Time loss Road space reduction No environmenal benefits either

Magnitude of time benefits Very real, but relatively small: in M£/yr in London: (surplus) = 50 net In Stockholm: (surplus) = 6 net Two comments: 1) = congestion costs. Relative to GDP of area: 0.1% in London, 0.02% in Stockholm 2) Much less than toll proceeds (1/5 in London, even less in Stockholm)

Minus: implementation costs Enormous in London : 500 M£/yer High in Stockholm : 100 M£/yr In both cases : eat up the decongestion benefits

Minus: public transport congestion costs PT congestion exactly like road congestion. Replace time loss by confort loss More PT users —> increase in PT congestion, for all PT users Poorly known. In Stockholm, data suggests increase in PT congestion costs = road decongestion costs

Conclusions 1)Road congestion costs vastly exagerated. 2)Can be reduced by tolls. A good policy when and if : a) congestion is severe, b) implementation costs are low c) PT congestion is moderate, or costs of PT supply increase are low 3) Paris road supply restriction policy worst