The Jerusalem Light Railway has provided the ancient city with new travel possibilities since it opened in August, but it is also proving controversial.
The borders in Jerusalem are invisible, and to an outsider barely perceptible. If you did not know they were there, you might - on a fleeting visit - miss them altogether.
But they are there.
In the 30-odd years I have been visiting Jerusalem, the city's political geography has changed dramatically.
The latest development is the Jerusalem Light Rail, a newly opened tram line that has been dogged by controversy, from the technical - with faulty traffic light phasing, and problems with ticketing - to, inevitably, the political.
The western part of Jerusalem, captured by Israel in 1948, is quite different in atmosphere, culture, language, facilities and ambience from most of the eastern part of the city. That was under Jordanian rule from 1948 until 1967 - when it, too, was captured by Israel.
Since then, Israel has greatly expanded Jerusalem's municipal boundaries, annexing large chunks of territory in a move that remains unrecognised internationally, and unilaterally redefining Jerusalem as its "eternal, undivided capital".
West to east
The new tram line passes uninterrupted from sovereign Israeli territory in West Jerusalem into the occupied Palestinian territory of East Jerusalem.
I started my journey at the eastern terminus in Pisgat Ze'ev, a Jewish suburb - or rather, as international law defines it, an illegal settlement - of villas, shops and apartment blocks.
The matrix board at the tram stop told me I had eight minutes to wait, so I sauntered over to a sweet shop. Three men were sitting out at a single table on the pavement. Uri, the shop owner, popped inside to make me a coffee, while I asked his friends about the tram.
"It's great," one said. "I can get into the city in 20 minutes, do my shopping, and be back home again without all the traffic."
"And the route?" I asked.
"It's very nice that it crosses from west to east," he replied, nodding as he carried on. "Arabs that live in Jerusalem don't have proper public transport - they deserve it."
He paused, and added thoughtfully: "I never spoke to an Arab before I rode this tram."
On board, as I swayed through East Jerusalem, it seemed I had picked a quiet day. The tram was less than a quarter full, a wary mix of ultra-orthodox Jews, middle-class Palestinians and a few tourists.
The most prominent presence was security - a uniformed guard standing at one end of the carriage, another patrolling the aisle and, if my instinct was accurate, more in plain clothes dotted among the passengers.
The station names were announced in Hebrew, Arabic and English, further evidence of the municipal authorities' desire to define this tram as a project of unification.
Yet most Palestinians I spoke to around the city had no intention of using it, many saying they viewed the service as another illegal attempt by a military occupier to exert control.
But Elias Naber, a business entrepreneur from the Palestinian city of Bethlehem, had a quite different view.
"The land has already gone," shrugged Elias. "The rails are already down. Whether I ride on the train or not makes no difference to the big picture. If it's convenient for me, I'll use it."
Further down the line, as we passed the 16th Century walls of the Old City - built by the Ottoman sultan Suleiman the Magnificent - the tram crossed one of those invisible borders into West Jerusalem - and suddenly it was rush hour.
Within a couple of stops, the whole tram was full, and from where I stood, it was all Israelis - raucous teenagers, grandmothers with shopping bags, business people, students.
The tram stayed packed and noisy until it reached the Bridge of Chords, an ethereally beautiful cable-stayed bridge designed by Spanish architect Santiago Calatrava, which marks the edge of the city centre.
After that, it was all suburbia. Schoolboys spread themselves across several rows, squabbling loudly till they were hushed by a shocked matriarch in a flowery dress. Parents with baby buggies rode home from a shopping mall.
At the western terminus, as grandpas and Jewish seminary students disembarked beside forested hills at the city's edge, I noticed a Muslim mother in a headscarf shepherding two small children out into the sunshine.
While I watched, they glanced around themselves, as if in a foreign country, then hurried across the platform into a tram waiting on the other side for the return journey back into the city.
Palestinian buses, of course, do not serve West Jerusalem and anyway, boarding city buses means running the gauntlet of attention from the driver and the route regulars.
But the tram is anonymous.
It presents opportunities for both sides to glimpse how the other half lives. Israelis have long had the chance to explore East Jerusalem, though few do. Palestinian sightseers in West Jerusalem, however - that is new.
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