The A1 motorway () is the longest motorway in Croatia, spanning . As it connects the nation's capital Zagreb, in the north of the country, to the second largest city Split on the shore of the Adriatic Sea, the motorway represents a major north–south transportation corridor in Croatia and a significant part of the Adriatic–Ionian motorway. Apart from Zagreb and Split, the A1 motorway runs near a number of major Croatian cities, and provides access to several national parks or nature parks, world heritage sites, and numerous resorts, especially along the Adriatic coast. The national significance of the motorway is reflected through its positive economic impact on the cities and towns it connects as well as its importance to tourism in Croatia.
The motorway consists of two traffic lanes and an emergency lane in each driving direction separated by a central reservation. All intersections of the A1 motorway are grade separated. As the route traverses rugged mountainous and coastal terrain, it has required 376 bridges, viaducts, tunnels and other similar structures in sections completed , including the two longest tunnels in Croatia and two bridges comprising spans of or more. There are 33 exits and 26 rest areas along the route. As the motorway is tolled using a ticket system and vehicle classification in Croatia, each exit includes a toll plaza.
A motorway connecting Zagreb and Split was designed in the early 1970s, and a public loan was started in order to collect sufficient funds for its construction. However, due to political upheavals in Croatia and Yugoslavia, construction of the motorway was labeled a "nationalist project" and cancelled in 1971. After Croatian independence and the conclusion of the Croatian War of Independence, efforts to build the motorway were renewed and construction started in 2000. The Zagreb–Split section of the route was completed by 2005, while the first sections between Split and Dubrovnik opened in 2007 and 2008. Construction costs incurred so far amount to 3 billion euro. The figure includes funds approved for construction work scheduled to be completed by 2013. The amount does not include construction cost related to the Lučko–Bosiljevo 2 section since that section was funded as a part of Rijeka–Zagreb motorway construction project through Autocesta Rijeka–Zagreb, current operator of that sector. The remainder of the A1 motorway, i.e., the sections south of the Bosiljevo 2 interchange are operated by Hrvatske autoceste.
Route description
The A1 motorway () is a major north–south motorway in Croatia connecting the capital of the country, Zagreb, to the Dalmatia region, where the motorway follows a route parallel to the Adriatic coast. As a part of the road network of Croatia, it is a part of two major European routes: E65 Prague–Bratislava–Zagreb–Rijeka–Split–Dubrovnik and E71 Budapest–Zagreb–Karlovac–Bihać–Knin–Split. The motorway is of major importance to Croatia in terms of development of the economy; especially tourism and as a transit transport route. This has been reflected by an accelerated development of regions connected by the A1 motorway. A part of the motorway is considered to be a segment of the Adriatic–Ionian motorway. Once the latter motorway's connecting sections are completed, those currently spanned just by the Adriatic Highway as well as two-lane roads in Slovenia and Albania, the A1 will achieve genuine importance as a transit route.
The motorway spans between Zagreb (Lučko interchange) and Ploče via Split. The route serves Karlovac via D1, Gospić via D534, Zadar via D8 and D424 and Šibenik via D533. The A1 motorway consists of two traffic lanes and an emergency lane in each driving direction along its entire length. The sole exception is Drežnik Viaduct where there are no emergency lanes. Almost all of the existing interchanges are trumpet interchanges, except for Lučko which is a stack. There are numerous rest areas along the motorway, providing various types of services ranging from simple parking spaces and restrooms to petrol stations, restaurants and hotels. , the motorway has 33 interchanges, providing access to numerous towns and cities and the Croatian state road network. The ultimate southern terminus of the motorway has been established to be near Dubrovnik.
Between the Lučko and Bosiljevo 2 interchanges, the motorway follows Pan-European corridor Vb, and is concurrent with the Zagreb–Rijeka motorway. The Bosiljevo 2 interchange distributes southbound A1 traffic flowing to Rijeka (via the A6 motorway) and to Split. That segment of the motorway is operated by Autocesta Rijeka–Zagreb, while the remainder of the motorway is operated by Hrvatske autoceste.
An automatic traffic monitoring and guidance system is in place along the motorway. It consists of measuring, control and signaling devices, located in zones where driving conditions may vary—at interchanges, near viaducts, bridges, tunnels, and in zones where fog and strong wind are known to occur. The system comprises variable traffic signs used to communicate changing driving conditions, possible restrictions and other information to motorway users.
It serves, either directly or via connecting roads, a large number of tourist destinations such as Bjelolasica in Gorski Kotar, a large number of Adriatic Sea resorts and several national parks and nature parks. In Lika region those are Plitvice Lakes National Park, Sjeverni Velebit National Park and Velebit Nature Park, while in Dalmatia the motorway serves Paklenica National Park, Telašćica Nature Park, Kornati National Park, Lake Vrana Nature Park, Krka National Park and Biokovo Nature Park. The route also provides links to a number of UNESCO World Heritage Sites such as Plitvice Lakes, Šibenik Cathedral of St James, Palace of Diocletian in Split and the Historic City of Trogir.
Toll
The A1 is a tolled motorway based on the vehicle classification in Croatia using a closed toll system integrated with the A6 motorway as the two connect in the Bosiljevo 2 interchange forming a unified toll system. Since the two motorways are operated by Autocesta Rijeka — Zagreb and Hrvatske autoceste, the toll collection system is operated jointly by the two operators. The toll is payable in Croatian kuna, euro, major credit and debit cards and using a number of prepaid toll collection systems including various types of smart cards issued by the motorway operators and ENC – an electronic toll collection (ETC) which is shared at all motorways in Croatia (except the A2 motorway) and provides drivers use of dedicated lanes at toll plazas and a discounted toll rates.
The A1 north of the Bosiljevo 2 interchange is operated by Autocesta Rijeka — Zagreb and the rest is operated by Hrvatske autoceste, both of which do not report company toll income separately for individual sections of various motorways. Total toll income reported by Hrvatske autoceste in the first half of 2011 was 508.1 million kuna (68.3 million euro). This figure pertains to the A1 south of the Bosiljevo 2 interchange as well as all other motorways operated by Hrvatske autoceste, however the A1 represents the longest and the busiest tolled motorway operated by Hrvatske autoceste. Toll income reported by Autocesta Rijeka — Zagreb for the first half of 2011 is 191.2 million kuna (25.7 million euro). This sum includes company toll income generated elsewhere, however the A1 section represents the busiest section of the motorway network operated by Autocesta Rijeka — Zagreb. Hrvatske autoceste and Autocesta Rijeka — Zagreb reported increase of the toll income compared to the same period of 2010 of 2.2% and 5% respectively.
Summertime and holiday queues at Lučko mainline toll plaza can be considerable, a problem exacerbated during the usual weekend-to-weekend tourist stays at Croatia's coastal resorts. In 2009, in an effort to address the problem, the Lučko mainline toll plaza was expanded to 15 lanes, and a single additional 10-lane toll plaza was built for fast cashless toll collection in Demerje. The Demerje toll plaza is available via a motorway fork accessible to the A1 northbound traffic only. Vehicles using the Demerje toll plaza default to the original motorway route immediately past the Lučko mainline toll plaza, between the plaza and the Lučko interchange. The faster cashless system has raised the nominal capacity of the road from 2,325 to 11,150 vehicles per hour. As of September 2010 northbound traffic leaving the A1 must exit the tolled motorway network, since the existing Zagreb bypass is not tolled, and then re-enter another tolled motorway. There are plans for the outer Zagreb bypass to be integrated into the tolled motorway network, as the ultimate solution for congestion at the Lučko toll plaza. That will require construction of a Horvati interchange south of the Lučko toll plaza.
Notable structures
A total of 361 structures—bridges, viaducts, flyovers, underpasses, passages, wildlife crossings, and tunnels—have been completed on the motorway between Zagreb and Vrgorac, and calculations indicate that 18.6 percent of the route between Zagreb and Split is located on those structures, which is a quite considerable percentage for a motorway of this length. By June 2011, Ravča-Vrgorac section was completed, including 5 viaducts, 4 flyovers and a tunnel. An additional 15 structures were built on the section between Vrgorac and Ploče, plus on the connection towards the city of Ploče.
Completed structures summary by sector Sector Total Bridges Viaducts Flyovers Underpasses Passages Tunnels Wildlife crossings Lučko (Zagreb) — Bosiljevo 55 3 9 13 13 16 1 - Bosiljevo 2 — Sveti Rok 116 16 17 38 29 3 5 4 Sveti Rok — Dugopolje (Split) 121 7 24 40 36 6 8 1 Dugopolje — Vrgorac 69 1 16 13 29 - 8* 2 Vrgorac — Karamatići** 15 - 7 2 2 - 4 - Total** 376 27 73 167 109 25 26* 7 *including 3 cut-and-cover tunnels. **Because of a common construction project and a common toll system, the totals also include the 5 km connector to the D425, from the Ploče interchange to the Karamatići toll plaza.
As of September 2010, there are seven tunnels longer than on the A1 motorway. The most notable among them are: the long Mala Kapela Tunnel between Ogulin and Brinje interchanges and the long Sveti Rok Tunnel between Sveti Rok and Maslenica interchanges. The Mala Kapela and Sveti Rok tunnels are not only the largest individual structures on the motorway but they are also the longest tunnels in Croatia. The tunnels separate three distinct climate zones. The Mala Kapela Tunnel spans between the continental climate of the central Croatia and the mountain climate of Lika, while the Sveti Rok Tunnel provides a link between Lika and its mountain climate and the Mediterranean climate of Dalmatia. Both of the Mala Kapela and Sveti Rok tunnels were originally operated as single tubes when they were opened for traffic in June 2005 until 30 May 2009, when the second tubes of the tunnels were also opened for traffic. The other major tunnels on the A1 motorway are the long Plasina Tunnel situated between Otočac and Perušić interchanges and the Grič, Brinje and Konjsko tunnels. Lengths of the latter three range between and .
The longest bridge on the A1 motorway is the long Dobra Bridge spanning Dobra River near Karlovac. Other major bridges on the route are the Gacka, Miljanica and Dabar bridges—all of them longer than . Also, the A1 motorway comprises the long Krka Bridge spanning Krka River and the long Maslenica Bridge spanning Novsko Ždrilo strait. The Maslenica and Krka bridges are particularly significant as their respective main spans are long.