Dense Traffic, High Heat, Steep Hills are Gaziantep’s Operating Reality
In this growing Turkish city, 45 million passengers depend on buses annually. Gaziantep Transportation Services Inc. (Gaziulaş), a subsidiary of Gaziantep Metropolitan Municipality, operates 380 buses serving 47 percent of the city’s bus transit. Buses represent 81 percent of public transportation across the city.
The operating environment is unforgiving: dense stop-and-go traffic, summer temperatures that stress mechanical systems, and steep urban inclines. The 55 routes vary dramatically—one stretches 120 kilometers with 64 stops, another compresses 35 stops into just 11 kilometers. Drivers navigate narrow roads, manage heavy passenger loads, and execute hundreds of acceleration-deceleration cycles each shift while maintaining tight schedules. Extended downtime directly impacts thousands of daily commuters.
“The dense traffic structure of Gaziantep and high summer temperatures put notable burden on public transportation vehicles,” says Mehmet Aykut Çakıroğlu, General Manager of Gaziulaş. “Environmental stress, operational intensity, and passenger dependency create demands where vehicle durability becomes fundamental.”
Torque Converters Replace Clutches, Continuous Power Replaces Shifting Interruptions
The 50 Otokar Doruk LE buses are equipped with Allison fully automatic transmissions featuring torque converter-based Continuous Power Technology™. The technology addresses three priorities identified by Çakıroğlu: “Driving comfort, operational continuity, and vehicle durability are critical factors in urban public transportation. Fully automatic transmissions provide a clear advantage in all three areas.”
The torque converter design eliminates clutch systems entirely, removing a wear-prone component that typically requires periodic replacement. Allison’s Continuous Power Technology™ delivers smooth, uninterrupted power transfer without mechanical shifting interruptions. “Allison fully automatic transmissions provide advantages in these conditions due to their high heat tolerance, torque converter structure, and continuous power delivery,” Çakıroğlu notes.
One Million Kilometers Per Bus: Maintenance Predictability Transforms Fleet Operations
The fleet averages over one million kilometers per vehicle after more than a decade of continuous service. “In a growing city like Gaziantep, where traffic density is high, technical reliability is crucial,” Çakıroğlu emphasizes. “The fact that our vehicles have exceeded 1 million kilometers serves as a strong reference for long-term performance.”
The operational benefits are measurable:
Maintenance Predictability: “The absence of wear-prone elements such as a clutch reduces the risk of failure, while more predictable maintenance intervals make operational planning easier,” Çakıroğlu explains. Gaziulaş can “minimize the impact of maintenance and repair times on operations and maintain higher fleet availability.”
Standardized Driver Performance: “By eliminating differences in gear usage caused by drivers, they contribute to achieving more consistent performance across the fleet and increase operational efficiency,” says Çakıroğlu. Automatic operation reduces physical fatigue throughout long shifts with hundreds of stop-and-go cycles.
Passenger Comfort: “Smooth take-offs, gentle acceleration, and smooth driving characteristics provide a positive experience in terms of passenger comfort,” Çakıroğlu notes, particularly important for standing passengers during peak periods.
Total Cost of Ownership: “Allison transmissions present a positive outlook in terms of total cost of ownership, thanks to reduced mechanical wear, predictable maintenance costs, and long service life,” Çakıroğlu confirms.
What 53 Million Kilometers Proves for Metropolitan Transit
Berk Gönenç, Allison Transmission Turkey, Middle East & CIS Sales Director, sees Gaziulaş’s experience as validation under real-world pressure. “Gaziulaş’s ongoing experience with Allison since 2013 clearly presents the durability of our fully automatic transmission technology in metropolitan public transportation,” Gönenç says. “The 53 million kilometers of field data is the most concrete indicator of performance and reliability under intensive urban usage.”
He emphasizes the operating environment’s significance: “The results achieved in a city like Gaziantep, characterized by high temperatures, dense traffic, and long routes, clearly demonstrate the contribution of Allison technology to operational continuity, driving comfort, and total cost of ownership.”
For transit authorities facing growing populations, intensifying congestion and budget constraints, Gaziulaş’s 53 million kilometers provides performance documentation at metropolitan scale under intensive conditions where frequent stops, thermal stress and demanding duty cycles are daily realities. As cities expand and public transportation becomes essential for sustainable mobility, durable drivetrain technology supports service reliability while managing total cost of ownership across extended vehicle life cycles.
For Gaziantep’s riders and the fleet managers who keep them moving, those 1,300 trips around the Earth mean reliable service, day after day, year after year.