In recent decades, trams have enjoyed a renaissance in France with around two dozen new tram systems now operating. However, trams are not the only way of delivering high capacity to an urban transport system.
The city of Metz, in north eastern France, has opted for a bus-based system. Two routes operate under the "Mettis" brand name, using bi-articulated vehicles. The "Mettis" services are provided by Le Met' (website only in French), the transport agency for Metz.
The "Mettis" comprises two routes, A and B, which form the backbone of Metz' public transport network. "Mettis" operates more-or-less entirely on segregated bus lanes.
Rather than having a single uniform livery, Le Met' vehicles carry one of four colours - yellow, green, blue or purple.
The colours are not specific to individual routes - a bus of any colour can be found on any route.
The segregation of "Mettis" from general traffic continues through the streets of Metz city centre.
The "Mettis" system has been designed to reduce car traffic within the city - "Mettis" serves three park-and-ride sites on the outskirts of the city, while general traffic has more limited access to the city centre.
Mettis stops are designed to a high specification, resembling stops on many modern tram systems. As well as shelters, they are also equipped with ticket vending machines.
Tickets cannot be bought on board Mettis vehicles.
The Mettis routes are integrated with other bus services, which share the segregated lanes in some places.
The other bus services provided by Le Met' fall into several categories.
Routes 1 to 5 are designated as "Ligne". This designation indicates that these five routes are the principal core services.
I found a mix of standard and articulated vehicles operating on the "Ligne" services.
The myth perpetuated by some commentators, that articulated buses belong on "wide continental boulevards" is shown here (as in so many cities where articulated buses operate) to be just that - a myth.
"Ligne" route 3 snakes its way through the narrow streets of Metz' historic centre.
The destination displays on newer vehicles alternate between showing the destination and "Je monte, je valide". This is a reminder to passengers that they must validate their tickets when boarding the bus.
The standard single-deckers have three sets of doors.
A further example of Metz' policy of traffic restraint in the city centre is illustrated by this vehicle negotiating a rising bollard.
Buses can activate the bollard, enabling them to pass, while other traffic is kept out of this stretch of road.
The five "Ligne" services are supported by less-frequent services designated as "Citeis". There are seven routes, numbered 11 to 17.
I found a mix of full-size and shorter-length buses in use on the "Citeis" services.
The shorter-length vehicles have two sets of doors.
A further group of services is designated "Navette". These operate mainly in the suburbs, providing connections with "Ligne" services. However, a couple of "Navette" routes reach the centre of Metz.
I found minibuses operating on "Navette" 83, which operates through the city centre.
Although most "Navette" routes are numbered between 82 and 91, route numbers 18 and 19 are also used for "Navette" services.
Finally, a dozen routes designated "Proxis" run to the outlying districts surrounding Metz. These services, numbered from 101 upwards, are infrequent with some journeys operating only if booked in advance.
Eight of the "Proxis" routes start from a bus terminus on the south side of Metz' main railway station.
I found some journeys were operated by single-deck buses...
...while others were provided by minibuses.
Fares on Le Met' services are simple. A single journey ticket costs €1.70 at the time of writing. This permits interchanges where necessary. The ticket can then be recharged at €1.50 per journey for subsequent journeys. An all-day ticket is available for €4 for one person, or for €8 for groups of up to 5 people travelling together. There is also a group ticket for single journeys, costing €6 for up to 10 people making one single journey together.
A network of bus routes serving the area beyond Metz is operated under the TIM brand.
These services operate from a bus station a short distance from the centre of Metz. Some of the services pass closer to the city centre, although "Mettis" routes A and B also link the bus station with the centre of Metz.
A relatively simple fare scale applies on TIM services. At the time of writing, single journey tickets are priced at €1.60, €2.60, €3.60 or €4.60, depending on the distance travelled. The €1.60 fare applies for journeys of up to 15 kilometres, rising to €4.60 for journeys of more than 35 kilometres.
There are also some bus services which operate in connection with the railway system. These operate from the bus stops on the south side of Metz railway station, rather than from the bus station.
Metz lies close to the high-speed railway line linking Paris with Strasbourg. There are some direct TGV trains from Metz to Paris, but there are also TGV services from Lorraine TGV station on the main line.
A shuttle bus operates from Metz to Lorraine TGV station, connecting with trains which call there.
There are also buses operating in conjunction with the local rail services. These carry similar "TransLor" branding to the local trains.
I found a three-axle vehicle as well as a two-axle one operating on the "TransLor" bus services.
Metz is served by long-distance and international coach services, which call in to the bus station.
I noted this coach towing a luggage trailer on a journey across central Europe to Bucharest. The journey from Metz to the Romanian capital takes more than 30 hours.
Finally, for tourists, a road train operates sightseeing tours of Metz from early April until early October.