1. R. Prud’homme (University Paris XII) M. Koning (University Panthéon-Sorbonne) P. Kopp (Panthéon-Sorbonne) Houston, May 18, 2008 PARIS LIGHT TRAIN IS THERE SOMETHING TO LEARN FOR HOUSTON? 1

2. GEOGRAPHY 2

3. 3

4. DAILY TRIPS IN PARIS AREA Paris Paris = 2,2M P. C. = 4 M G.C = 4,8M 8,6 (10%) 5,4 (22%) 3 (63%) 2,7 (58%) 1,1 (63%) 2 (23%)

5. 5 THE TRAIN’S NAME IS T3

6. POLITICAL CONTEXT Congestion, CO2 Price versus quantity: London toll, Paris, road diet Light train is a symbol of modernity. A political and mediatised success (mayor re- elected and media love it) Need for CBA 6

7. T3’s CONSEQUENCES T3 switch's riders from bus to light train Different groups of citizens are concerned : PT users (T3, subway) Car users, on Maréchaux boulevard, radials, ring road We study the variations of their economical surplus (welfare approach) And the environmental impact (one of T3’s objectives ). 7

8. WHO ARE THE USERS? Ex-bus (50%) or subway (33%) users. Low modal shift from cars (2,7%) 144,000 bus trips * km before 256,000 train trips * km today (2,56 km in average length) 100,000 users per day Time gains and comfort gains Decrease mobility’s price and increase welfare gains 8

9. Time gain. The average speed is now 20 km/h ( before 16 km/h) Waiting time increased: +0,5 minute The travel cost (in time) of a trip decrease by 0,438 min/riders * km With a time value of 10,2 €/h, the annual gains is 4,47 M€ Comfort gains. Tricky question (contingent evaluation, willingness to pay for comfort) Simplifying assumption: comfort gains are in the same order of magnitude than those of time (4,47 M€) LIFE IS BETTER FOR TRAIN USERS 9

10. AND WORTH FOR CAR USERS Car traffic has fallen from 198,000 riders * km to 116,000 riders * km (-82,000) But Modal report Cars to T3 is low: -7,000 riders * km Did they disappear? Structural decrease (Paris public policy + oil price’s increase) : -10,000 riders * km Real decrease in traffic = 65 000 riders * km (-36%) Where are the others? 10

11. On the Ring Road : Cost gap equal to the roundabout way plus the waste of time necessary to reach the ring road Average length of trip on the boulevard = 4 km Roundabout way = 2 * 400 m = 800 m Average speed = 20 km/h With these parameters : ∆cost = 0,6 min/car * km= 0,102 €/rider * km HERE THEY ARE! 11

12. A QBQB QAQA B’ D B P B’ PBPB PAPA ObOb OaOa Trips Cost 12 C D A CLEAR PICTURE StayOut QCQC Switch

13. Shift to Ring road, Q B Q C =55,000 riders * km Mobility decrease, Q C Q A =10,000 riders * km Welfare decrease = - 6,85 M €/ year + Wastes of time on radials : - 1,83 M € 13 COST CONSEQUENCES

14. RING ROAD CONGESTION More cars on the ring road means more congestion The traffic has increased of 55,000 riders * km/day (42 300 trips * km/day=BC) Debates on congestion costs in urban areas: –With INFRAS’ value (2,70 €/riders*km), we find an annual cost of 45,06 M€. –We use Prud’homme-Sun’s model of congestion (2000). It uses a « disaggregated approach » by distinguishing congestion costs with respect to the speed of displacement (Koning, 2008)

15. Speed (km/h) Distribution (%) Shift+ (veh * km) Cm(q) (€/trip * km) Congestion costs (€/day) 5<x<104,061 71715,927,306 15<x<206,362 6902,54+6,833 35<x<403,291 3920,37+515 70<x<7514,186 2600,01+63 33.1M€ per year 15 RING ROAD: COST OF CONGESTION

16. ENVIRONMENTAL IMPACT Two important relations - Number of cars and CO 2 are + correlated - CO 2 emission is an inverse function of speed under 50 km/h Hence : –Suppression of buses (-) –Modal report Cars/Train (-) –Decrease car speed on Blv Maréchaux (+) –Decrease in car speed on RR (+) –Longer trips to access the BP (+) 16

17. CO 2 EMISSION ON THE RING ROAD According to US Ministry of Energy : If s< 50 km/h : CO 2 (kg/km) = 0,624 – 0,00925 * s If s> 50 km/h : CO 2 (kg/km) = 0,16 By crossing this relation with the speed- density relation, we can deduce the « marginal emission » on the ring road (function of density): CO 2 M (kg/veh * km) = 0,00231 * q 17

18. Before (tons) After (tons) Change (tons) Bus Suppression1,0650-1,065 Modal report7090-709 Longer trips01,114+1,114 Speed decrease on Bd Maréchaux11,78712,538+752 Speed decrease on RR+3,023 Total+3,115 0.1M€ 18 BAD CO 2 BALANCE

19. COSTS AND BENEFITS Initially (M€)Annual (M€) Investment-444,34 FunctionningNd ∆ surplus operator+0,84 ∆ surplus users CT : Time gains+4,47 Comfort gains+4,47 Subway’s decongestion+4,57 ∆surplus car users : On Maréchaux-6,85 On radials-1,83 Externalities : Congestion BP-33,31 CO2 emissions-0,10 Total-444,34-27,74 19

20. WHAT DID WE LEARN? Negative NPV of 888 M€ with a 30 years horizon Impossible to find a positive IRR Environmental objective is not reached Car users (from poor suburbs) are the losers of the T3’s project The T3 users are the winners. 60% are richer Parisians When only 15% of the cost is paid by the municipality, the rest by the region 20

21. Cities need a bundle of means of transportation, cars and PT Among PT, the choice btw subway, train and bus hardly rely on density Subway or light trains are good for high density zone and/or mass commuting trip Buses are cheaper and more flexible elsewhere 21 CONCLUSION

22. A CONSERVER 22

23. A QBQB QAQA B F E PAPA ObOb OaOa q p 23 C D A CLEAR PICTURE StaySwitch QCQC PBPB Stop

24. Assumption: the shift follows the same distribution law –Speed-density relation V(q) = 77,1 -0,25 * q –Private cost I(q) = 0,12 + 1,3 * 10,2/V(q) –Social cost S(q) = I(q) + I’(q)*q –Marginal congestion cost : Cm(q) = S(q) –I(q) = 3,315 * q/(77,1- 0,25 * q) 2 24