Background & Objectives

The fleet above desctibed is operated in the teritory of the Municipality city of Rome.
Rome has an extension of 1.200 square km, and counts 2.800.000 inhabitants.
The transport network covers 2.144 km, 355 lines of surface PT are in operation.
The vehicles are used just for collective passenger transport mainly on the urban environment.

Electric buses have been running in Rome since 1989, and since 1996 a quite large fleet of 42 buses (5 mt buses; max capacity: 27 people; equipped with pb-acid 585 Ah batteries; autonomy of 45 km) has been operating on three lines with a total production of 1,200,000 vehicle-km per year, (which means about 1% of the service offered by the surface network).

Company:

ATAC is the agency of the Municipality of Rome in charge of the planning, monitoring and control of mobility in Rome; including PT operations as well as the control of private traffic and parking, the management of the integarted ticketing system.
ATAC is the owner of all the vehicles and the networks in Rome, it counts 1.600 employees.
The Technical department to which I belong is in charge of following innovations in the field of PT vehicles and of issuing tenders for the purchase of the new buses etc.

Size/Implementation Quantity:

ATAC runs 400 CNG buses, 51 electric buses, 12 hybrid buses, and the remaining are diesel, most of them are EURO III compliant.
In the next future 36 more electric middle sized buses will be in operation.

Motivation

• implementation of a Zero Pollution Project in urban areas characterized by very narrow roads,
• extension of the project (ongoing)

Implementation

ATAC, the PT Agency in Rome, has so far purchased 10 new electric mini buses with the features detailed below, which have been added to the 42 already in service.

Service currently operated with e-buses:

number of lines: 5
total network length = 20,2 Km
vehicle-Km/year produced: 1.200.000

Concerning the traditional electric buses (5m length) 10 new have already been put in operation
Characteristics:

• Max length: 5,1m
• Max width: 2,3 m
• Passenger capacity: 27+1
• seats: 8
• standing room : 19
• Engine : c.c - 24,5 kW;
• Batteries: Pb acid - 585 Ah
• Voltage : 72 V

Autonomy : 45 Km

Range of use: best fit up to 190 Km/day with intermediate battery recharging admitte

Conclusions

Electric buses have proved to be instrumental for the success of the Zero Pollution Project as they are able to serve an environment characterized by very narrow roads. They are greatly appreciated by the users: besides being non pollutant, the most appreciated qualities are: comfort and silence.
The qualitative relevance of lines operated by clean vehicles was confirmed by the appreciation showed by people. Awareness of the need to use clean transit increased from 53% to 76%, along with satisfaction which changed from 3.6 to 3.96 (1-5 Lickert scale), becoming the most "satisfactory measure" of the MIRACLES group.

Strong points of the traditional electric buses:

• Flexibility: The vehicle´s capacity to carry out the function foreseen in the framework of the network, namely the possibility of effecting the service inside the zones of the centre where the labyrinth of streets would not have permitted the use of larger vehicles,
• Reliability: This result is also due to the choice made by ATAC of entrusting maintenance to the vehicle manufacturer itself, with a total servicing contract which has recently been renewed;
• Good users´ acceptance: The excellent reaction by the citizens at large

Weak points:

• Autonomy: the batteries allow - also considering the characteristics of operation - an autonomy of about 6 hours (about 45 kilometres), after which the vehicle has to be driven back to the depot where the run-down battery set is removed and replaced by another appropriately recharged one. The operation of disassembly and reassembly is simple and rapid, however the margin of autonomy inevitably implies a lack of flexibility in the organisation of the service, with the costs that this entails;
• Capacity: The capacity of 27 passengers permits their utilisation exclusively on routes envisaging a limited load
• Comfort: due to the absence of air conditioning, a problem felt more by the drivers than the passengers.

Costs:
Operation costs and the fleet size in comparison with the service to be offered are obviously higher than those afforded by conventional buses.>

Perspective:

The role of electric vehicles will keep on being a key element for the success of the project, but an upgrading of their performance will require advanced technological solutions.
As a matter of fact, present performance could be inadequate owing to the longer length of the routes where the vehicles would depend on an on-board electric source of energy, batteries in particular.
The objective of the measure is to continue to enlarge the electric bus fleet through the purchase of 36 new "medium sized" buses, to be operated onto two new lines for a total length of 14 km. It is planned that they will produce 700.000 vehicle-Km/year.

The ambitious plan to procure 36 more "medium sized" e-buses (8-9 meters length) has been on going during the MIRACLES Project lifetime, and finding a partner technical has been much more demanding then expected. The procurement has had the following requirements:

1) Batteries:
Replacement of Pb-Acid batteries with the new Metal-Hybrid pack. First tests carried out in 2002 have shown that:

the range of use has doubled;
a complete refit of traction and battery management equipment is necessary.

2) Vehicle:

Length: up to 9.0 m
Width: up to 2.3 m
Capacity: 36 passengers minimum

Anyway during the relevant reporting period technical tests have been performed on a prototype bus along some "difficult" paths in Rome in order to test the main performances of the vehicles, which are the following: 135 km covered with one battery charge, max speed: 55km/h, 15% slope covered.